700R4 Swap Into M1009

akonitony

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Is the lockup switch a toggle switch you hit at highway speeds to lock the converter? If that's the case, when you reduce speeds off the highway (exit ramps), do you have to flip it again to unlock it?


Thanks!
Nope, I wired the VB to only go into lockup in 4th gear, so in 1st through 3rd, it has no lockup. Once it downshifts into 3rd, or drops below 55 MPH in 4th, it comes out of lockup automatically. Basically, the toggle switch is there to shut off lockup in 4th gear, which I rarely do since it will only go into lockup at around 55 MPH or higher anyways. For towing, I leave it in 3rd gear on the selector column unless I'm on a long, flat road where I know I can keep a steady pace, then I will put it into 4th and lockup. I also have an HD TC with a carbon fiber clutch element in it (the stock TCs have a paper element that tears too easily) and a super servo for 4th gear which increases the holding capacity of the 2/4 band by some 40%, so it is built to tow in OD. However, the 6.2 diesel does better in 3rd, or direct drive when there are a lot of hills. I also have an auxilary cooler for the TC rigged inline after the radiator cooler, so towing out of lockup will not overheat the TC.
 
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akonitony

New member
Sorry bud.GM never used a 34 spline output shaft. 27 &32 only.
OK Dave, if you insist. I went out and counted 34 splines on the output shaft I changed out on the last 700R4 I built, which was shortly after this thread started (I've been out of the shop I have in Alabama since then and developing our property in Florida), but I guess I could have counted wrong by 2 splines. From what the Klune catalog lists, the only spline count they have for the output shafts is 31, so maybe we are both wrong. I have never used the 27-spline output shaft, but I do know they exist, and are not preferrable, and my main point earlier was to steer anyone away from using a 27-spline input shaft. With all the info I put out earlier, the fact you chose to split hairs over a spline count tells me you aren't the kind of person with whom I need to get into an argument because you probably will never quit.
 

ODdave

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Dude, Count the OUTPUT shaft. I dont want to argue but GM only used 27 spline output shafts in the 700r4. (in gm aplications). As a mater of fact NONE of the big 3 use 34 splines. GM used 27 in the th350/ 700r4/ 4l60e/ t5/ nv3500/ etc. They used 32 splines on th400/ 4l80e/ nv4500.
Dodge uses 23 and 29 spline outputs
Ford uses 31.

You may have a book, But I have the tranmissions AND transfercases. I have done A LOT of interchanging and swapping and am VERY familiar with this stuff. I can post pics if needed



What transfer case are using if you have 34 splines?
 

Croatan_Kid

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You're right, the inputs are 27 or 30 and the 30 being prefered. Mine was a 30 spline unit. I had a pretty sweet aftermarket converter in front of it and a bunch of mods. I wasn't gunna let no 6.2 scare my transmission :beer:



Not stirring the pot, but the outputs on 700R4s...where the t-case connects to the tailshaft of the transmissions (to avoid ANY confusion)...are 27 spline.


My current NV4500/205 is 32.
 

Timber

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akonitony, I'm not sure you are wrong. I drove a 1983 K5 305/TH700R4 to college, it'd been in the family since new. The transmission died around 125K. I got two quotes on the rebuild and I remember the more expensive quote was 'with the later model upgrades,' this was 1989 or so. But the shop manager told me it came with the beefed up input shaft, 27 to 30 spline and also some kind of more aggressive XXX-vane pump. My parents opted for 'back to stock', seems like it was a $1400 dollar rebuild at the dealership vs an $1800 dollar rebuild. If the 27 vs 30 spine input shaft is a myth, then they were selling it at the dealership service bays in the late 80's.
 

jj

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akonitony, in post# 31, you mentioned "for a grand, you can add an overdrive to a 400, and have the best of both worlds." I am intrigued by the idea of a $1000 overdrive for a TH-400! Please elaborate.
 

ODdave

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Dude. just edit the post so the spline count is right and be done with it. I deleted my argumentitive posts so they didn't waste space and peoples time.
 

akonitony

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ODdave

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The feelings are mutual bud. And there are several kits for Allisons. Increasing line pressure is nice, but if you don't beef up apply pistons and reprogram shift points, you are just peeing in the wind - or worse, inviting disaster. Judging by the way my 6.6 Duramax can smoke the tires when it catches second gear and give a good chirp when it hits 3rd, I think I've done a little more than increase line pressure. Like I said earlier, I never really paid attention to the spline counts on output shafts, and just ran out to the shop and counted it out as 34 right before I typed that post. Rather than being a smartipants and saying "34 HUH? - Try 27", you could have said something like "I think it's 27 on the output shaft" or something like that, and I would have not responded in a harsh manner at all. As far as being wrong or a liar, they are not the same thing, I never called you a liar, and you were wrong about it being 27 splines - is was 32, so in all actuality I was 2 off and you were 5 off, so I was closer to right than you - nah, nah, nah, nah... nah:drool:
Post a pick of a 32 spoons 700 and I all be humbled. I didn't say "I think" because I Know. There 27. Learn what your looking at. lol.
 

akonitony

New member
Post a pick of a 32 spoons 700 and I all be humbled. I didn't say "I think" because I Know. There 27. Learn what your looking at. lol.
That would be kind of hard for me to do at the moment Dave since my shop is on my property in Alabama, and I'm currently down at our Florida property. I guess I could call my neighbor who is looking after the place for me when I'm not there, and tell him to take a pic of the the shaft if I can get him to find it, but being he is not a transmission man, I doubt that is going to have a great outcome either. I did call my mentor who taught me a bunch about building trannies and who was himself trained by GM, specifically for Cadillacs, and he said he never bothered to count splines on an output shaft, and has no idea how many are on the 700R4s, but he thinks they are all the same count, just different lengths, so you probably are right Dave. I also have taken your earlier suggestion of deleting posts, which you said you were going to do - Happy now?
I don't feel so bad if the guy who I respect more than anyone on the planet for his knowledge with transmissions also doesn't know the spline count for the output shafts of 700R4s. If you could see him come up with some of his homemade shift kits, and realize he knows what he is doing, you'd be humbled by that for sure.
Is this :deadhorse: yet, or what?
 

ODdave

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Geese. You shure boogied out of town. You said you counted them not 3 hours ago. Hey it is what it is. I know some insanely intelligent people as well so not much surprises me.
 

akonitony

New member
Geese. You shure boogied out of town. You said you counted them not 3 hours ago. Hey it is what it is. I know some insanely intelligent people as well so not much surprises me.
I said I counted them right when I was posting the the first post on this thread. I was typing about the different output shafts, looked them up in my catalog and typed how many types there were, then went out to the shop and found one and counted 34 splines on it. I was probably in a hurry and grabbed a 32-spline TH400 by mistake. That'll teach me to try and be helpful.
 

Recovry4x4

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Spline count aside, putting a 700R4 trans in an 09 with 3.08 gears is pointless and will burn up in short order.
Well, you don't have to use overdrive and the 3.06 first gear really helps with the 3.08 axle gears. Maynard ran that setup for years and swore by it. The overdrive is only one of the benefits of the 700R4.
 

wayne pick

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Well, you don't have to use overdrive and the 3.06 first gear really helps with the 3.08 axle gears. Maynard ran that setup for years and swore by it. The overdrive is only one of the benefits of the 700R4.
Understood, but as eluded to by southdave, 3.73s would be a better fit RPM wise, and overdrive could actually be used with 3.73s. The 3.06 first gear is a tad low for a 4.56 axle ratio. My 1031 shifts out of "grandma" at 13 MPH, LOL. I could adjust that by fiddling with the TV cable, but as you are well aware, thats not recomended and second to third gear slip will result. I do enjoy the berefit of overdrive, and in OD lockup, it drops the RPMs down again almost like a 5th gear. I guess it's all about which side of the transmission you want to use for your aplication.:smile:
 

Croatan_Kid

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GM pumped out a crap load of 80s model trucks with a 350/700R4 and 3.08 gears. Got one sitting in the yard. Not sure it'd burn it up, but I agree that they suck big time. I'd be tickled pink if it had 4.10s in it, even with 31x10.50s. It's even worse with a 6.2, just because of the lack of power...then again with the gas motor, it just makes it lug and drink fuel big time. If it was any more aerodynamic than the broad side of a barn, it'd get great mileage up around 90 mph :D
 

Whitfield

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I'm actively working on gathering pieces for a 700R-4 swap. Punching in the numbers (RPM + Trans + T-case + Gear ratio + Tire Size) in this chart gives me all the details in an easy to read format where I can compare the different mods side by side. http://www.grimmjeeper.com/gears.html


700R-4 @ 2800 RPM's 235x85-16 = 80+ MPH (Not sure this brick will ever see 80 MPH)

I see that 1984 and later 700R-4 transmissions are upgraded to a 30 spline input at the converter but I don't see much talk about tail shaft spline count... What will I need to do to mate my 700R-4 to my Stock M1008 NP208.





just finished mine, trans was free, spent 300 on torque converter, 60 on flex plate, 100 on tq lockup kit, 25 on bracket and tv rod, 16 on tv cable and 200 on transfer case w/adapter total=686. I'm getting 20-21 with an average speed of 55-60, at 55 i'm at 1900 rpm's, 70 is 2500 rpm's.

@ sandcobra164 and bshupe, will need a tv cable bracket, they don't make these any more so will have too find one in a junkyard or make one, there is a pic on this thread. will need a tv cable rod, this hooks onto side of pump/throttle linkage and connects to tv cable at the back of motor. I called local chevy dealer, they can get them through there classic vehicle distributor for $25. Will need a tv cable, I got mine at local parts store for $16. New flex plate, also might want to consider getting a new torque converter, I got the flex plate for $60 and the TC for $100, it is a 1600 stall with lockup. Also will need the lockup kit, I got mine for $100. This is where I got TC, Flexplate, and Lockup kit Bowtie Overdrives . The 700r4 is only 1/2 an inch longer than the turbo 400, I didn't need to move the trans/transfer case crossmember, will also need an NP208 from the back of a turbo 350, make sure it comes with adapter, this is a direct bolt up to the back of the 700r4, NO modifications required! Drive shafts will NOT need to be modified, they will bolt right up to the NP208 that came of the turbo 350. That's it, as far as shifter linkages, and trans cooler lines for trans/transfercase, everything is the same no modifications required. Will need to use dipstick tube from the 700r4 it is a little different than the turbo 400.
 

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