• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

 

3 Speed Shifter to 4 Speed Shifter- Modifications

McSpeed

Well-known member
333
293
63
Location
Palmer, AK
I've installed a number of overdrive upgrade units to older GM cars. There is a company called Shiftworks that I usually use for the shifter. They make new detent gates and even new shifter plates for the indicators that look stock at first glance. In fact, I'm doing a 700R4 in a 1974 Corvette later this month and will be using them for that as well. It is very much like what you are doing.
 

McSpeed

Well-known member
333
293
63
Location
Palmer, AK
I've installed a number of overdrive upgrade units to older GM cars. There is a company called Shiftworks that I usually use for the shifter. They make new detent gates and even new shifter plates for the indicators that look stock at first glance. In fact, I'm doing a 700R4 in a 1974 Corvette later this month and will be using them for that as well. It is very much like what you are doing.
 

TOBASH

Father, Surgeon, Cantankerous Grouch
Steel Soldiers Supporter
3,173
2,800
113
Location
Brooklyn, NY
I think to remove stuck/difficult bolts I might drill them out like rivets.

Fast, easy, and no reach around/under.
 

MattNC

Well-known member
222
270
63
Location
Raleigh, NC
TOBASH, can you tell me more about the transmission you decided to go with? 765R4, is that an upgraded 700R4? I've been putting a ton of miles on my 998 since getting it doing hunting and farm trips and love it except on the highway. Not screaming at 60 mph would be nice. If I fix my injector pump leak and add a 4th speed I also figure I will not have to spend so much quality time at the gas station as well!
 

MattNC

Well-known member
222
270
63
Location
Raleigh, NC
Thanks also for this great writeup on the shifter how-tos. The engineer in me loves diving into how things work. Its a lot of work to share and I appreciate it!
 

TOBASH

Father, Surgeon, Cantankerous Grouch
Steel Soldiers Supporter
3,173
2,800
113
Location
Brooklyn, NY
TOBASH, can you tell me more about the transmission you decided to go with? 765R4, is that an upgraded 700R4? I've been putting a ton of miles on my 998 since getting it doing hunting and farm trips and love it except on the highway. Not screaming at 60 mph would be nice. If I fix my injector pump leak and add a 4th speed I also figure I will not have to spend so much quality time at the gas station as well!
765R4 is upgraded 700R4. 1900 stall torque converter. Rebuilt by Bowtie Transmissions in California. Nikki was the receptionist handling the purchase, and she is knowledgeable and intelligent and extremely helpful.

Tranny should be bulletproof for my requirements.

I have no affiliation with this vendor.

Sorry to hijack the thread with this reply.:derailed:
 

gray1027

New member
19
1
3
Location
Pensacola, FL
I am in the middle of doing my 4L80e Conversion and will do a write up on that part of the project, but I was unable to find anything on modify the stock shifter. Here is my adventure...

Modification of 3 Speed Shifter:
One of my initial concerns with the 4-speed conversion was the shifter mechanism. I am very turned off with the price that the market is getting for these ($500-$700 in 2019), the controller is expensive, but some options at least give us options. I see no reason for this pricing beyond fake supply and demand and I saw no reason the 3 speed can’t be made to work.
With the 2 transmissions out, I used an angle finder to map the angles as the gear change lever is moved through the detents. 3 main differences (Park is a large angular change, 7 positions vs 5, and angle spacing) were noted. I would have been ok with only OD and D, but as it turned out, I was able to get all 7.
After removing the stock shift gate (this is the piece of metal that has the Detents that lock the shifter in position that lines up with the internal Transmission Detents) I was able to create my own template and gates. This worked a lot easier than I anticipated. I expected to have to use CAD to layout a gate and get a machine shop to cut it out but was able to make it on my workbench with an angle grinder and metal bandsaw. Stock and replacements are both 3/16” mild steel (I also expected it to be hardened, but it is not, and I really don’t think it needs to be after mulling the idea of making the new one hard). I had steel scraps from an old weight bench, but Tractor Supply, Lowes, Home Depot, etc for under $20.
· First Step- install ¼” Rivnuts (I bought a $12 kit at Harbor Freight). Stock configuration with uncaptured nuts on the bottom is silly.
· I used a magnetic Angle finder on both transmission shift levers (I used the TH400 Shift lever on the new 4L80e) in all the detent positions and on the stock installed shift mechanism (see picture with measurements). This would be key to making the REV1 Gate later.
· I removed the Shifter mechanism (the linkages were already removed during tranny swap steps)
· Removed the Shift Gate Light & the neutral safety switch
· Disassembled the entire mechanism. There are 2 Roll Pins, roll pin punches are recommended, especially for the transfer case one, it is tiny.
· The shift gate is secured to the body by 3 rolled rivets- Drill & Grind them to remove gate
· I used the Old Gate as a template to create new 7 position gates (rev1). Note- there was the Neutral safety hole AND a reverse light hole already. The shifter rod has tabs to activate both of these.
o REV1 Gate
· Both new gates were drawn out on paper first. I laid a piece of paper over the stock gate and traced the basic shape, all 5 holes and the stock gate positions. Laying this paper of the main shift body, I lined the 5 holes up and was able to trace the hole for the pivot arm of the shifter, key step as this is a master measurement that is needed to get the Arcs for the new gates correct. I then used a compass to get the Inner and Outer Arcs drawn on the template, then used a protractor to mark the Cuts.
· In my new Gate, I used the Reverse hole position for the new location for Neutral safety switch position (where park is now)
· Based upon my Rev1 and angle measurements, I enlarged the shift area rectangle in the body and the top plate. I enlarged the back side (towards the rear of truck) only by maybe ¾”, this eliminate one of the bolts that holds the top plate on the body, but 2 bolts are more then enough for a nonstructural member in my opinion.
· This still only allowed me to get 4 maybe 5 of the gate positions on m Rev1 gate. This was largely driven by the huge angular thrown with the P to R positions.
· I reassembled the mechanism & installed the Rev1 Shifter and re-hooked up the stock linkage J bolt, moving the trunnion on the J bolt. While this worked, almost as expected, I was barley getting in to the D position and the whole thing was wonky and not confidence inspiring! I then drilled a 2[SUP]nd[/SUP] hole in the Transmission Shift Lever. Stock hole was 3.125” CL to CL. I went to 2” CL to CL, this is what I ended up using in the final product.
· This New shorter throw lever would not work at all. Too much play in the whole assemble. Back to the Drawing Board
o Rev2 Gate
· I ordered a Military 4L80e shift jack assembly (P/N: 12447182, E-bay @ $11.39 shipped!). This uses to rods and a second pivot arm vs the TH400 J-Bolt assembly.
· The new Shift Lever Bracket installs through 2 of the pan bolts. Once installed, I made up 2 rods with Swivel Trunnions (needed 1additional from Kascar Item# 6001696 @$3.22). 1 rod is a straight piece of 3/8-18 threaded rod connecting the lower hole on the Shift Lever Bracket, to the New Hole in the shift lever arm, this is 7-3/8” CL to CL. I used nuts on the end of this to lock it but will end up peening the rod when I finalize & paint it. The 2[SUP]nd[/SUP] was an offset 3/8 threaded rod, connecting the top hole back to the Shifter Mechanism. Easily bent in my bench vise.
· Now that I had the Linkage straightened out, I Shifted the mechanism while using a Sharpie & the angle finder to move the shift lever with the button fully depressed to mark the REV1 Gate, that was still installed, (also measured the angles to verify later) when the transmission engaged each gear position. I remove the shifter mechanism at this point
· I created the REV2 template, then the metal gate, using these marks and validating them with the angle readings (tough to get 100% accuracy with the sharpie). The Lever Bracket & Shorter Arm allowed all 7 gear positions in the REV2 Gate fitting in the “lengthened” shifter slot (would be worth checking if the stock slot might not be “lengthened”
· After cutting the rough shape, use small file, grinder, Dremel, etc. to fine to the Detents. I used the shifter to ensure a good fit.
· The stock gate was attached to the housing with 3 special rivets. .500” thin heads on ~.280 rivets that were peened over. My initial plan was to weld back through these holes, but instead found that ¼-20 bolts were more than sufficient to hold it in place. There were 3, but the hole in the back end is now covered by the 2 or 1 gear position. I found that with the through bolts there is no play & with the bolts being at the front end, where the Park is, I am fine with it. IF I ever spot movement, I will simply spot weld it in place. I reefed on it with out the shift linkage in place, and where my detents are deeper then stock, it was very secure.
· Drill out the new hole for the neutral safety (this was the exact position in the TH400 gate then was drilled & tapped for the reverse light switch). The neutral safety is 9/16”-18, the reverse is bigger. I drilled the reverse hole undersized for now, if I ever want to add a reverse light switch, it will be easy to do.
· Reassemble and install.
· Check the linkage to ensure the transmission matches the new gate. You do not want to put pressure on the transmission detents. I actually did a semi assembly incase I needed to tweak.

I still have to build a new LED backlit position indicator, but that will come later, as well a repaint and re-rubber the top plate once I complete the whole 4L80e Swap.


In full disclosure, I had this thing in and out many times, hence the early comment about the Rivnuts! Waiting for parts (9/16 tap, trunnions, etc) and other parts of the transmission swap made this take a few days longer, but overall, I think this is a more then viable option. I will update this as I complete the finishing touches and if I end up having any problems. Overall, less then $15 for this modification
Take away, if you are like me and want to do it, save the money and mod your Shifter.
View attachment 782205View attachment 782207View attachment 782202View attachment 782208View attachment 782198View attachment 782206View attachment 782203View attachment 782200View attachment 782199View attachment 782197View attachment 782201View attachment 782209
Well Good Sir,

Have you gotten any closer to mass producing these gems?

R/
Gary
 
59
8
8
Location
kingston/ NH
I haven’t done anything towards producing them. My next step is to work on getting a shift indicator 3D printed.
The modification really was very simple, especially to someone who can change out a transmission.
For those on a budget, this is the way to go.

Well Good Sir,

Have you gotten any closer to mass producing these gems?

R/
Gary
 

Jevon

New member
10
18
3
Location
Maine
I am in the middle of doing my 4L80e Conversion and will do a write up on that part of the project, but I was unable to find anything on modify the stock shifter. Here is my adventure...

Modification of 3 Speed Shifter:
One of my initial concerns with the 4-speed conversion was the shifter mechanism. I am very turned off with the price that the market is getting for these ($500-$700 in 2019), the controller is expensive, but some options at least give us options. I see no reason for this pricing beyond fake supply and demand and I saw no reason the 3 speed can’t be made to work.
With the 2 transmissions out, I used an angle finder to map the angles as the gear change lever is moved through the detents. 3 main differences (Park is a large angular change, 7 positions vs 5, and angle spacing) were noted. I would have been ok with only OD and D, but as it turned out, I was able to get all 7.
After removing the stock shift gate (this is the piece of metal that has the Detents that lock the shifter in position that lines up with the internal Transmission Detents) I was able to create my own template and gates. This worked a lot easier than I anticipated. I expected to have to use CAD to layout a gate and get a machine shop to cut it out but was able to make it on my workbench with an angle grinder and metal bandsaw. Stock and replacements are both 3/16” mild steel (I also expected it to be hardened, but it is not, and I really don’t think it needs to be after mulling the idea of making the new one hard). I had steel scraps from an old weight bench, but Tractor Supply, Lowes, Home Depot, etc for under $20.
· First Step- install ¼” Rivnuts (I bought a $12 kit at Harbor Freight). Stock configuration with uncaptured nuts on the bottom is silly.
· I used a magnetic Angle finder on both transmission shift levers (I used the TH400 Shift lever on the new 4L80e) in all the detent positions and on the stock installed shift mechanism (see picture with measurements). This would be key to making the REV1 Gate later.
· I removed the Shifter mechanism (the linkages were already removed during tranny swap steps)
· Removed the Shift Gate Light & the neutral safety switch
· Disassembled the entire mechanism. There are 2 Roll Pins, roll pin punches are recommended, especially for the transfer case one, it is tiny.
· The shift gate is secured to the body by 3 rolled rivets- Drill & Grind them to remove gate
· I used the Old Gate as a template to create new 7 position gates (rev1). Note- there was the Neutral safety hole AND a reverse light hole already. The shifter rod has tabs to activate both of these.
o REV1 Gate
· Both new gates were drawn out on paper first. I laid a piece of paper over the stock gate and traced the basic shape, all 5 holes and the stock gate positions. Laying this paper of the main shift body, I lined the 5 holes up and was able to trace the hole for the pivot arm of the shifter, key step as this is a master measurement that is needed to get the Arcs for the new gates correct. I then used a compass to get the Inner and Outer Arcs drawn on the template, then used a protractor to mark the Cuts.
· In my new Gate, I used the Reverse hole position for the new location for Neutral safety switch position (where park is now)
· Based upon my Rev1 and angle measurements, I enlarged the shift area rectangle in the body and the top plate. I enlarged the back side (towards the rear of truck) only by maybe ¾”, this eliminate one of the bolts that holds the top plate on the body, but 2 bolts are more then enough for a nonstructural member in my opinion.
· This still only allowed me to get 4 maybe 5 of the gate positions on m Rev1 gate. This was largely driven by the huge angular thrown with the P to R positions.
· I reassembled the mechanism & installed the Rev1 Shifter and re-hooked up the stock linkage J bolt, moving the trunnion on the J bolt. While this worked, almost as expected, I was barley getting in to the D position and the whole thing was wonky and not confidence inspiring! I then drilled a 2[SUP]nd[/SUP] hole in the Transmission Shift Lever. Stock hole was 3.125” CL to CL. I went to 2” CL to CL, this is what I ended up using in the final product.
· This New shorter throw lever would not work at all. Too much play in the whole assemble. Back to the Drawing Board
o Rev2 Gate
· I ordered a Military 4L80e shift jack assembly (P/N: 12447182, E-bay @ $11.39 shipped!). This uses to rods and a second pivot arm vs the TH400 J-Bolt assembly.
· The new Shift Lever Bracket installs through 2 of the pan bolts. Once installed, I made up 2 rods with Swivel Trunnions (needed 1additional from Kascar Item# 6001696 @$3.22). 1 rod is a straight piece of 3/8-18 threaded rod connecting the lower hole on the Shift Lever Bracket, to the New Hole in the shift lever arm, this is 7-3/8” CL to CL. I used nuts on the end of this to lock it but will end up peening the rod when I finalize & paint it. The 2[SUP]nd[/SUP] was an offset 3/8 threaded rod, connecting the top hole back to the Shifter Mechanism. Easily bent in my bench vise.
· Now that I had the Linkage straightened out, I Shifted the mechanism while using a Sharpie & the angle finder to move the shift lever with the button fully depressed to mark the REV1 Gate, that was still installed, (also measured the angles to verify later) when the transmission engaged each gear position. I remove the shifter mechanism at this point
· I created the REV2 template, then the metal gate, using these marks and validating them with the angle readings (tough to get 100% accuracy with the sharpie). The Lever Bracket & Shorter Arm allowed all 7 gear positions in the REV2 Gate fitting in the “lengthened” shifter slot (would be worth checking if the stock slot might not be “lengthened”
· After cutting the rough shape, use small file, grinder, Dremel, etc. to fine to the Detents. I used the shifter to ensure a good fit.
· The stock gate was attached to the housing with 3 special rivets. .500” thin heads on ~.280 rivets that were peened over. My initial plan was to weld back through these holes, but instead found that ¼-20 bolts were more than sufficient to hold it in place. There were 3, but the hole in the back end is now covered by the 2 or 1 gear position. I found that with the through bolts there is no play & with the bolts being at the front end, where the Park is, I am fine with it. IF I ever spot movement, I will simply spot weld it in place. I reefed on it with out the shift linkage in place, and where my detents are deeper then stock, it was very secure.
· Drill out the new hole for the neutral safety (this was the exact position in the TH400 gate then was drilled & tapped for the reverse light switch). The neutral safety is 9/16”-18, the reverse is bigger. I drilled the reverse hole undersized for now, if I ever want to add a reverse light switch, it will be easy to do.
· Reassemble and install.
· Check the linkage to ensure the transmission matches the new gate. You do not want to put pressure on the transmission detents. I actually did a semi assembly incase I needed to tweak.

I still have to build a new LED backlit position indicator, but that will come later, as well a repaint and re-rubber the top plate once I complete the whole 4L80e Swap.


In full disclosure, I had this thing in and out many times, hence the early comment about the Rivnuts! Waiting for parts (9/16 tap, trunnions, etc) and other parts of the transmission swap made this take a few days longer, but overall, I think this is a more then viable option. I will update this as I complete the finishing touches and if I end up having any problems. Overall, less then $15 for this modification
Take away, if you are like me and want to do it, save the money and mod your Shifter.
View attachment 782205View attachment 782207View attachment 782202View attachment 782208View attachment 782198View attachment 782206View attachment 782203View attachment 782200View attachment 782199View attachment 782197View attachment 782201View attachment 782209
Having just bought a 1994 HMMWV for pennies on the dollar, I have discovered that the aftermarket is based upon "FORCED" supply and demand: some dudes bought up ALL of the military surplus, dried up the competition, and now we have C-pillars for $460-$700 plus $199 shipping vs the same dimensions from Raybuck for 22 lbs of rocker panels with $30 in the shipping cost. Everything HMMWV-related is highway robbery (minus grommets and stickers, lol) FYI, most large road signs are aluminum and are easily door-sized and even 40x76" roof-sized. This 4-speed shifter "gate plate" work is gold.
 

Mogman

Moderator
Staff member
Moderator
Steel Soldiers Supporter
5,815
8,081
113
Location
Papalote, TX
Having just bought a 1994 HMMWV for pennies on the dollar, I have discovered that the aftermarket is based upon "FORCED" supply and demand: some dudes bought up ALL of the military surplus, dried up the competition, and now we have C-pillars for $460-$700 plus $199 shipping vs the same dimensions from Raybuck for 22 lbs of rocker panels with $30 in the shipping cost. Everything HMMWV-related is highway robbery (minus grommets and stickers, lol) FYI, most large road signs are aluminum and are easily door-sized and even 40x76" roof-sized. This 4-speed shifter "gate plate" work is gold.
Welcome to the world of HMMWV, maybe some research done beforehand would have been wise.
 

Jevon

New member
10
18
3
Location
Maine
Welcome to the world of HMMWV, maybe some research done beforehand would have been wise.
For a $1000 investment, a 25-year *want*, and an entire salvage yard, with nearly any transmission/transfer case combo swap you can think of, who would have hesitated at the sight of a cornered, inflated, gouging, dog-eat-dog market? Thankfully, Tribal GSA access allows for direct interaction with Demilitarized surplus, often donated.
 

springer1981

Well-known member
844
1,147
93
Location
Maine
There are certainly some that are capitalizing on the demand for some parts. To the shifter itself, it is still available directly from AM General in costs about $600, new from the manufacture (See pic below). Depends what you want for your truck. The new one has the correct gate obviously as well as the labeling, lights, boot and location for reverse light switch etc. Not to mention the labor saved by simply removing it from the box to install it. With a little searching I found one brand new for about $450 and added the reverse light switch and tab for another $30. Used ones can be found for less. The cost difference below is the reverse light switch.

When you see some places that resell genuine AMG parts they may just be trying to make a profit and not necessarily price gouging. I found it pays to do a lot of searching and asking around.

shifter.jpg
 

Bulldogger

Well-known member
Steel Soldiers Supporter
1,397
566
113
Location
Quantico VA
There are certainly some that are capitalizing on the demand for some parts. To the shifter itself, it is still available directly from AM General in costs about $600, new from the manufacture (See pic below). Depends what you want for your truck. The new one has the correct gate obviously as well as the labeling, lights, boot and location for reverse light switch etc. Not to mention the labor saved by simply removing it from the box to install it. With a little searching I found one brand new for about $450 and added the reverse light switch and tab for another $30. Used ones can be found for less. The cost difference below is the reverse light switch.

When you see some places that resell genuine AMG parts they may just be trying to make a profit and not necessarily price gouging. I found it pays to do a lot of searching and asking around.

View attachment 875021
I'd add that I've seen prices on the AMG website vary depending on their stock levels. I bought direct from them, and I didn't pay the above price when I did 18 months ago. Want it now = pay what sellers are asking. Have time and patience = deals will come and go.
Bulldogger
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks