3 Speed Shifter to 4 Speed Shifter- Modifications

58
4
8
Location
kingston/ NH
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.
Rivnuts.jpgIMG_20191029_205245081.jpgSwitch Positions.jpgIMG_20191029_201254258.jpgAngle Measurements.jpgGate Progression.jpgNeutral Safety 2.jpgFinal Rev2 Gate Installed.jpgEnlarged Shift Slot.jpgAlternate Lever Hole.jpgNew Shifl Linkage.jpgRoll Pin Punch.jpg
 

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Bulldogger

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Wow! A thorough answer to a question many of us have. Lots to digest here. Thank-you for documenting it so well. Someone will ask if you will provide the parts, or modify 3spd shifters if sent you, so it might as well be me...
Bulldogger
 
58
4
8
Location
kingston/ NH
The original plan was to get a CAD file and have a company run a batch. Before I go down the path, I want to work with at least 1 guy who is doing a Swap to ensure that my final design worked with their transmission and no other interference's. I did the write hoping others would do it for sure.
 

Crapgame

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Huh. If you have a CAD file, having some gear selector quadrants water jet cut in 4140 chrome moly steel, then plated, sold with some hollow rivets might be a solution for the market.
 

Bulldogger

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I'd cheerfully buy an unplated version! I am hoping to tackle a powertrain swap next year and want to DIY a 4-speed shifter. Your solution to remap the gates and retool the shifter is definitely of interest and I don't mind paying for a kit that solves me fussing with a protractor.

Bulldogger
 

TOBASH

Father, Surgeon, Cantankerous Grouch
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Can you post an accurate size of your paper cut-outs with the detent troughs?

Post your images in true size and high def with a ruler in inches and millimeters next to it?

Essentially I would like to print out a perfect paper copy in order to etch a piece of steel and cut out the pattern perfectly.

Yes I see his images on the Green ruled table, but a true sized properly scaled reproducible image would be awesome.

Maybe also a CAD file.

Thanks!

Excellent work.

Mods...Stickie?

T
 
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Awol

Active member
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Nice work!

I've done this with other vehicles, using the stock shifter with upgraded transmissions. I've always wondered why people didnt do it with the Hmmwv?

I'm sure you could sell a bunch if you make them
 

TOBASH

Father, Surgeon, Cantankerous Grouch
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I'm getting a little confused re.: the following:


· 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.

You have pics, and I understand the throw of the shift is too long and needs adaptation, but I think I'm getting hung up in the verbiage on actually fixing the issues caused by lengthening the throw of the shifter.
 
58
4
8
Location
kingston/ NH
I think I gave too much information. Too much of novel vs here is what you need to do.
1) there is no CAD at this time. If I can validate my template works, it would get in to CAD.
2) I will provide a high resolution picture/scan with a scale. A couple key measurements too, any measurements will be imperial only, no metric!
3) my worry for anyone else, there is an important correlation between shift lever throw (think arc around transmission shift stub) and shift gate detects is key. Lots of complicate math, but I Think I can give the measurements of the 4 items that will make this easy to duplicate.
 

dilvoy

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What about the T Case Shifter?
That will need modification too and you won't have the same leverage as the correct shifter with that short ball topped bent handle so maybe make that longer above than the amount you lengthen it below the pivot point.
 
58
4
8
Location
kingston/ NH
I added a legend mark (1" between the lines) and used the scanner to make a copy. I tested this and the printed copy matched perfectly.

1) Using this template, Cut a 3/16" steel gate.
2) Lever at Transmission needs to be 2" CL to CL
3) Stock 4L80E Shift Lever Bracket P/N: 12447182 (mounted to transmission)
4) Rod between Lower hole on above bracket and shift lever on transmission needs to be 7-3/8" (7.375") CL to CL.
A rod between the shift bracket and the shifter mechanism will need to be made. With the transmission in P (full back) and the shifter in P (full forward) bend up a rod that matches CL to CL.

If anyone is going to try, let me know and I will help as best I can.
So who is going to try this out?
 

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TOBASH

Father, Surgeon, Cantankerous Grouch
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What about the T Case Shifter?
That will need modification too and you won't have the same leverage as the correct shifter with that short ball topped bent handle so maybe make that longer above than the amount you lengthen it below the pivot point.
Am I missing something? Why would t-case shifter need anything?
 

TOBASH

Father, Surgeon, Cantankerous Grouch
Steel Soldiers Supporter
1,438
232
63
Location
Brooklyn, NY
I added a legend mark (1" between the lines) and used the scanner to make a copy. I tested this and the printed copy matched perfectly.

1) Using this template, Cut a 3/16" steel gate.
2) Lever at Transmission needs to be 2" CL to CL
3) Stock 4L80E Shift Lever Bracket P/N: 12447182 (mounted to transmission)
4) Rod between Lower hole on above bracket and shift lever on transmission needs to be 7-3/8" (7.375") CL to CL.
A rod between the shift bracket and the shifter mechanism will need to be made. With the transmission in P (full back) and the shifter in P (full forward) bend up a rod that matches CL to CL.

If anyone is going to try, let me know and I will help as best I can.
So who is going to try this out?
Awesome!!!!

i have a brand new to me custom rebuilt 765R4 waiting to go in. I’m debating making this rather than using the shifter I bought. Then I can sell the 4L80e shifter that I bought to recoupe some $.

Thanks
 
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58
4
8
Location
kingston/ NH
I used a NP241C, which is backwards shifting compared to the stock NP218 I had. But the stock lever worked, I just had to move the trunnion farther out on the stock rod. The 4L80e is only 1.5" longer so I assume that the stock shifter rod will work with the NP218 or NP242 cases.

There are no Detents in the shifter for the transfer case, instead it relies on the detents in the transfer case. My leverage is perfectly fine.

What about the T Case Shifter?
That will need modification too and you won't have the same leverage as the correct shifter with that short ball topped bent handle so maybe make that longer above than the amount you lengthen it below the pivot point.
 
58
4
8
Location
kingston/ NH
You might have to tweak this for your Transmission... using an angle finder, map out the angle differences through the gear shifts on the transmission (either the lever or right on the flats). If they are the same as the 4L80e, the only thing you might need to tweek is the 7-3/8" dimension on the 1st shift link rod

Awesome!!!!

i have a brand new to me custom rebuilt 765R4 waiting to go in. I’m debating making this rather than using the shifter I bought. Then I can sell the 4L80e shifter that I bought to recoupe some $.

Thanks
 

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Last edited:

Crapgame

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I've seen the 4speed LED gear shift indicators on ebay, would the positions from your quadrant plate be different from the A2 shifter assy? The quadrant plate in the A2 is arc-shaped, with spring loaded detent in the gear shift shaft. I looked in the -24P-1, no part number is given for the individual guts inside the assembly. CAGE 19207 is TACOM Tank and Automotive Command, but looking at the Part#, it shows an Orscheln 84 and Date Code KJ241. Orscheln Products LLC, 1177 N. Morley Street, Moberly, MO 65270-2736. The quadrant itself is stamped 51053-2. I sent them a message asking about the sub assembly parts

The market is artificially depressed, the M11XX are just being hacked to pieces for scrapping ,the demillers don't give a flying fornicate about sub parts, although they have figured out to at least leave the long blocks together on the frame remnant but in the process they destroy the 4L80E gear shifter assy. The only way you get one is if you scrap an A2 series truck or stumble upon a DLA replacement part assy.

I dunno, maybe Orscheln may be up for selling some support parts, at least the important guts that can be used to convert the TH400 shifter to 4L80E.

A2 Shifter 12460111.jpg
 
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58
4
8
Location
kingston/ NH
Crapgame- your research skills far outweigh mine. I found the original P/N's and MFG information from the TM, but was unable to find any of the sub parts. That quadrant gate is what I started looking for. I don't have a 4 speed shifter to compare is SxS with a 3speed, but looking at it from the TM and the gate you posted don't look like they would be a drop in solution.

I agree, the government is depressing the market, but that has caused a huge inflation in some of these parts, shifters, are just one large example. These have no other application, and as a wear part, it is really robust. The 4 speed upgrade crowd has created this environment or these shifters would go for $50.

I test drove mine this weekend and the modified shifter worked perfectly



I've seen the 4speed LED gear shift indicators on ebay, would the positions from your quadrant plate be different from the A2 shifter assy? The quadrant plate in the A2 is arc-shaped, with spring loaded detent in the gear shift shaft. I looked in the -24P-1, no part number is given for the individual guts inside the assembly. CAGE 19207 is TACOM Tank and Automotive Command, but looking at the Part#, it shows an Orscheln 84 and Date Code KJ241. Orscheln Products LLC, 1177 N. Morley Street, Moberly, MO 65270-2736. The quadrant itself is stamped 51053-2. I sent them a message asking about the sub assembly parts

The market is artificially depressed, the M11XX are just being hacked to pieces for scrapping ,the demillers don't give a flying fornicate about sub parts, although they have figured out to at least leave the long blocks together on the frame remnant but in the process they destroy the 4L80E gear shifter assy. The only way you get one is if you scrap an A2 series truck or stumble upon a DLA replacement part assy.

I dunno, maybe Orscheln may be up for selling some support parts, at least the important guts that can be used to convert the TH400 shifter to 4L80E.
 

Crapgame

Active member
457
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Location
Navarre, FL
I think the biggest roadblock to the shifter box removal is Amy's idiotic decision to use a bolt through the top and a nut from the bottom, no scrapper is going to take the time to put two guys on a truck, one up.one down, to remove the boxes without damage. $2.00 in 4 rivet nuts should have been the install method right from the assy line.
My GEP-T long block came with part of the transmission and transfer shift levers still attached to the linkages but not enough to convert the 3speed box.
The Orscheln side plates are pop riveted to the top plate. Let's wait & see if they are open to sell support parts, w would be nice to buy at least the shift assys and quadrant plate. I would think LABOR assembling the box would be more than the plated parts. Even if you could get the side plates and guts for under $300 in quantity it would be an improvement until some middle man negotiates an exclusive then we're back up to $500 shift boxes.
I'll measure the hole spacing for the LED Gear Indicator later. The LED Indicators are $100 and up.
 
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