? replace TH400 w/700R4 ?
Thread Starter
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
? replace TH400 w/700R4 ?
Ran across a good deal on a fresh low mile 700R4 from 91 V8 Caddy ... trans clean as a pin in&out ... elderly driver had accident & Caddy was totalled on side.
Most of the posts I see about this are folks w/ TH350 ... not TH400.
Who's swapped out from TH400 to 700R4? What did you do regarding crossmember & driveshaft? I'd like to hear from folks who've either done it themselves or had it done ... TH400 to 700R4.
This 71 C3 has TH400 w/ removeable crossmember. What's involved regarding driveshaft? ... and ... crossmember? I have the ability to locally fabricate/mod Xmember and mod DS if need be ... I don't need to mailorder either.
*edit* I respect each opinion regarding 2004R vs 700R4 ... & I'm not disputing any ... but I'm seeking specific info about xmember & ds in TH400 to 700R4 swap. Trans choice debate best at another thread please ... here I need specific info about xmember & ds in TH400 to 700R4 swap.
Most of the posts I see about this are folks w/ TH350 ... not TH400.
Who's swapped out from TH400 to 700R4? What did you do regarding crossmember & driveshaft? I'd like to hear from folks who've either done it themselves or had it done ... TH400 to 700R4.
This 71 C3 has TH400 w/ removeable crossmember. What's involved regarding driveshaft? ... and ... crossmember? I have the ability to locally fabricate/mod Xmember and mod DS if need be ... I don't need to mailorder either.
*edit* I respect each opinion regarding 2004R vs 700R4 ... & I'm not disputing any ... but I'm seeking specific info about xmember & ds in TH400 to 700R4 swap. Trans choice debate best at another thread please ... here I need specific info about xmember & ds in TH400 to 700R4 swap.
Last edited by jackson; Oct 11, 2006 at 12:02 AM.
Safety Car
Joined: Oct 2004
Posts: 3,725
Likes: 5
From: Minnesota
Well I did the swap. It takes time but isn't too difficult.
I fabbed up my own crossmember mount in a couple of hours using some 4" square tubing.
The driveshaft needs to be shortened about 2 3/4".
I also moved the parking brake pulley over a little for driveshaft clearance. The rest of the swap has been posted here a million times so I'm sure you're familiar with it.
I fabbed up my own crossmember mount in a couple of hours using some 4" square tubing.
The driveshaft needs to be shortened about 2 3/4".
I also moved the parking brake pulley over a little for driveshaft clearance. The rest of the swap has been posted here a million times so I'm sure you're familiar with it.
Last edited by jdmick; Oct 10, 2006 at 09:48 AM.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
I am facing my 4th 3/4 clutch pack in my 700 tranny, you are much better off with a 200 4r in there, and forget the 700, not only some 50 lbs lighter, but much more reliable....don't matter who or how the 700 was built, just go go various sites and see the amount of kits and fixes for that 3/4 clutch pack, and that tells you something.....all kinds of throttle valves, sleeves, modifications unlimited, and so forth....
where as the list of mods for the 200 4r is about 10% of that, and it lasts.....
Just this morning, somewhat chilly, for Florida anyway...temp around 60f...and the 700 slipped greatly, engine revving freely enough into 3rd gear.....I lifted, tranny shifted, when it warmed up slightly it was ok for today.....but short term/long term, it's history ....outta there one last time....
tired of dicking around with this 700 junk.....it's a design problem and there is no cure.....
lob 50 lbs off too boot....
going to pick up a 200 4r core this afternoon.....
where as the list of mods for the 200 4r is about 10% of that, and it lasts.....
Just this morning, somewhat chilly, for Florida anyway...temp around 60f...and the 700 slipped greatly, engine revving freely enough into 3rd gear.....I lifted, tranny shifted, when it warmed up slightly it was ok for today.....but short term/long term, it's history ....outta there one last time....
tired of dicking around with this 700 junk.....it's a design problem and there is no cure.....
lob 50 lbs off too boot....
going to pick up a 200 4r core this afternoon.....
Safety Car
Joined: Oct 2004
Posts: 3,725
Likes: 5
From: Minnesota
Originally Posted by jackson
Thanks, was your old trans a TH400 or TH350?
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Talk to the folks at bowtieoverdrives. They sell the crossmember and shifter mods if you don't want to mod yours. If you want to modify your crossmember that can be done too. As far as the driveshaft goes, you just have to get a good measurement and have yours shortened. You will have to have a different yoke- get one from a TH350, 4-speed, or an 82-96 Corvette with 700R4/4L60/4L60E. You must have a Corvette (removable) type yoke for ease of installation. You cannot use a stock 82 driveshaft in pre 80 C3, so don't waste time finding one. It is a nice swap, 91 should be a good transmission-you want 88 up. I bought an 88 Caprice for the trans the other day but it had already been swapped for an 85-bummer. Good luck with it.
Pro
Joined: May 2002
Posts: 518
Likes: 17
The 700R4 can be built as strong as a 2004R if the builder knows what he's doing. My Toy Shop modified 89 700R4 from a Formula F-Body has run behind a 455 ft/lb 406 for 15+ years now. 700's are better if you have a 3.36 rear gear or higher (lower numerically), while the 2004R is better with rear gears of 3.55 or lower (higher numerically).
700's come in many styles, though the Vette and 4X4 ones are not good for C3 use (different output shaft lengths).
The standard 700 has two different Tailhousings available, the standard without a mount, and the S10 style that has a mount in the standard TH400 position. This is the one that I used, and all I had to do on my 71 Coupe was to drill a couple of holes in the stock Crossmember a little farther back, move the Hand Brake Cable Pulley over a little, and shorten the Driveshaft. The Shifter Cable, Cooler Lines, 12V Wiring, and Speedo Cable all worked fine. You'll also have to do something about your Steering Interlock if so equipped.
You can use the other 700 Tailhousing and fab up a plate similar to how the TH350's mount as well, though it's more work.
Get a good one and it'll be fine behind 500HP or less...
Doug
700's come in many styles, though the Vette and 4X4 ones are not good for C3 use (different output shaft lengths).
The standard 700 has two different Tailhousings available, the standard without a mount, and the S10 style that has a mount in the standard TH400 position. This is the one that I used, and all I had to do on my 71 Coupe was to drill a couple of holes in the stock Crossmember a little farther back, move the Hand Brake Cable Pulley over a little, and shorten the Driveshaft. The Shifter Cable, Cooler Lines, 12V Wiring, and Speedo Cable all worked fine. You'll also have to do something about your Steering Interlock if so equipped.
You can use the other 700 Tailhousing and fab up a plate similar to how the TH350's mount as well, though it's more work.
Get a good one and it'll be fine behind 500HP or less...
Doug
Originally Posted by jdmick
TH400. The odd thing is that the mount for the 700r4 is closer to the engine than the TH400 even though the tranny is almost 3 inches longer.
Last edited by doug_dayson; Oct 10, 2006 at 07:35 PM.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by doug_dayson
The 700R4 can be built as strong as a 2004R if the builder knows what he's doing...
I have met many people running 700s with lots of power. You just have to have a builder that knows what they are doing AND set up the TV cable correctly. That is critical.
Originally Posted by doug_dayson
..700's come in many styles, though the Vette and 4X4 ones are not good for C3 use (different output shaft lengths)...
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Pro
Joined: May 2002
Posts: 518
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I know it's a small difference in length (.75" or something?) between the C4 and F-Body Tailshafts. So the 82 C3/S10 style Tailhousing works with the Vette 700R4's Output Shaft eh? Good to know (as the only WOT in 4th Valvebodies are from Y/F Bodies)...
I believe the 82 C3/S10 Tailhousings are one and the same (the mount is similar to a TH400's, back on the Tailhousing itself).
By all means do NOT use a 6 cyl 700R4 (just it's Tailhousing)!
Yes, for either 2004R or 700R4 the TV Cable adjustment is most critical as it controls Line Pressure. Improper adjustment here dooms either trans to a short life...
Doug
I have met many people running 700s with lots of power. You just have to have a builder that knows what they are doing AND set up the TV cable correctly. That is critical.
There is nothing wrong with the length on a C4 Corvette 700R. I have 1 in my car from a 92 (actually a 4L60, not a 4L60E). The problem is that you have to use an 82 tailhousing (that's what I have) or an aftermarket. There is a company that makes them with a mount like an 82 (or an earlier TH350 or TH400) on the tailhousing-Phoenix something maybe?. A C4 700R4 case does not have the holes near the pan drilled like all the others do. You can drill and tap if you want, the pad and raw holes are there. A 4wd 700R does have the wrong tailshaft so you don't want those unless you have another core transmission of the same vintage to get the tailshaft and have it rebuilt. You also don't want a trans from an Astro or S10 with a 4.3, they are not as strong. I also think there was a 700R in some 2.8 Camaros that have a different bellhousing bolt pattern. F-body and Corvette use the tailhousing to attach to the differential so it is difficult to adapt to a "flat" mount. Trucks and B-body use the pad next to the pan for a mount, this is what the BowTie crossmember uses.
I believe the 82 C3/S10 Tailhousings are one and the same (the mount is similar to a TH400's, back on the Tailhousing itself).
By all means do NOT use a 6 cyl 700R4 (just it's Tailhousing)!
Yes, for either 2004R or 700R4 the TV Cable adjustment is most critical as it controls Line Pressure. Improper adjustment here dooms either trans to a short life...
Doug
Originally Posted by markdtn
I have met many people running 700s with lots of power. You just have to have a builder that knows what they are doing AND set up the TV cable correctly. That is critical.There is nothing wrong with the length on a C4 Corvette 700R. I have 1 in my car from a 92 (actually a 4L60, not a 4L60E). The problem is that you have to use an 82 tailhousing (that's what I have) or an aftermarket. There is a company that makes them with a mount like an 82 (or an earlier TH350 or TH400) on the tailhousing-Phoenix something maybe?. A C4 700R4 case does not have the holes near the pan drilled like all the others do. You can drill and tap if you want, the pad and raw holes are there. A 4wd 700R does have the wrong tailshaft so you don't want those unless you have another core transmission of the same vintage to get the tailshaft and have it rebuilt. You also don't want a trans from an Astro or S10 with a 4.3, they are not as strong. I also think there was a 700R in some 2.8 Camaros that have a different bellhousing bolt pattern. F-body and Corvette use the tailhousing to attach to the differential so it is difficult to adapt to a "flat" mount. Trucks and B-body use the pad next to the pan for a mount, this is what the BowTie crossmember uses.
Drifting
Joined: Sep 2003
Posts: 1,325
Likes: 6
From: FRANKLIN GA
Originally Posted by mrvette
I am facing my 4th 3/4 clutch pack in my 700 tranny, you are much better off with a 200 4r in there, and forget the 700, not only some 50 lbs lighter, but much more reliable....don't matter who or how the 700 was built, just go go various sites and see the amount of kits and fixes for that 3/4 clutch pack, and that tells you something.....all kinds of throttle valves, sleeves, modifications unlimited, and so forth....
where as the list of mods for the 200 4r is about 10% of that, and it lasts.....
Just this morning, somewhat chilly, for Florida anyway...temp around 60f...and the 700 slipped greatly, engine revving freely enough into 3rd gear.....I lifted, tranny shifted, when it warmed up slightly it was ok for today.....but short term/long term, it's history ....outta there one last time....
tired of dicking around with this 700 junk.....it's a design problem and there is no cure.....
lob 50 lbs off too boot....
going to pick up a 200 4r core this afternoon.....
where as the list of mods for the 200 4r is about 10% of that, and it lasts.....
Just this morning, somewhat chilly, for Florida anyway...temp around 60f...and the 700 slipped greatly, engine revving freely enough into 3rd gear.....I lifted, tranny shifted, when it warmed up slightly it was ok for today.....but short term/long term, it's history ....outta there one last time....
tired of dicking around with this 700 junk.....it's a design problem and there is no cure.....
lob 50 lbs off too boot....
going to pick up a 200 4r core this afternoon.....
THe 700's were built to handle torque. That's why GM put them in their trucks. Ever seen a truck with a 200 in it?. The 200's were built for high HP, low torgue engines like the Buick Grand Nationals turbo v-6's. Alot of the extra 50 lbs is in the beefiness of the case, it adds strength for the torque it can handle. I also feel that the reason you can find so may aftermarket performance parts for the 700's is because they can be made to handle more HP and Torque than the 200's can.
The 700's do have a limit of how much torque (this is what kills them) they can handle in stock or mildly modified form. I know this from experience, I've broken 3 of them already. But with aftermarket parts designed to overcome their shortcomings they make a pretty good trans. It just takes the right PERFORMANCE TRANS BUILDER to make it happen. The guy who built the last one that's still in mine now, also builds for other racers in this area. There is one he built that has been behind a 800 HP 69 Chevelle (not a light car) on nitrous that has held up for 2 years now at the track in front of big slicks.
Find someone who knows what they are doing, the 700's are pretty good trans.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by doug_dayson
I know it's a small difference in length (.75" or something?) between the C4 and F-Body Tailshafts. So the 82 C3/S10 style Tailhousing works with the Vette 700R4's Output Shaft eh? Good to know (as the only WOT in 4th Valvebodies are from Y/F Bodies)...
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
The holes in the crossmember for exhaust pipes need to be out further for a straighter shot to the back since the TH-700R4 is wide. Gkull has posted about doing it.
Here's something not normally mentioned.
"Also note that the GM 700R4 (4L60) transmission does not route fluid to the cooler unless the TCC is locked."
http://www.diy-efi.org/gmecm/papers/tcc.txt
"it does but it is not alot"
Chris
christoforos Kokkonis,general motors transmission specialist
www.ckperformance.com
street/strip/drag race automatics,planetary gears,shafts,drums ,valve bodies.
Here's something not normally mentioned.
"Also note that the GM 700R4 (4L60) transmission does not route fluid to the cooler unless the TCC is locked."
http://www.diy-efi.org/gmecm/papers/tcc.txt
"it does but it is not alot"
Chris
christoforos Kokkonis,general motors transmission specialist
www.ckperformance.com
street/strip/drag race automatics,planetary gears,shafts,drums ,valve bodies.
Last edited by Ganey; Oct 12, 2006 at 08:39 AM.
