Transmission question...

[anziconda]

I have a 84 chevy 4x4 with a 700r4 auto trans in it. After a hard night of wheeling, its slipping pretty bad. Does anybody know if I could bolt a th-400 or a th-350 right in or do I need an adapter? This is the second 700r4 in 5 years and I getting convinced that they are overpriced pieces of schmidt!!! Any input is welcome...have to get the sled tote ready for winter.

 

[Squirrelchaser]

Either trans will bolt to your engine, not sure if the lengths are the same.

 

[anziconda]

Yeah, that is what I'm wondering...I think the 700r4 is longer and if I bolted the 350 or 400 into it I'd have to modify the crossmember and lengthen/shorten the drivelines. If thats the case I wouldn't be saving much money.
Anybody else???? More info needed!!!

 

[Motley Doo]

Now now, the 700r4 was a great transmission, with the proper upgrades, it's hard to find a better over-drive tranny. Did you check the TV cable? how many miles are on it? Who was it built by?

 

[LeeDoo]

^^^ Would you care to elaborate on the upgrades? My 700R4 lasted 15k and I'm not happy. Was also wondering about putting in a TH-400, like my Dad did on his '90 3/4 ton suburban.

 

[sandrailboy]

a th400 will bolt up to the engine the legnth of the 400 is the same as the 700 the t case is the problem you need a larger spline input to put the t case on to a 400.... what i would do is find a 400 trans and t case out of a 1 ton truck most came with a 400 and a np208 t case....i have done this many times it is a easy conversion i got a 400 and a 205 tcase in my garage all it needs is the adapter....

 

[anziconda]

^^^ Would you care to elaborate on the upgrades? My 700R4 lasted 15k and I'm not happy. Was also wondering about putting in a TH-400, like my Dad did on his '90 3/4 ton suburban.

Thats funny, thats exactly what mine lasted, right between 15000-20000

 

[anziconda]

a th400 will bolt up to the engine the legnth of the 400 is the same as the 700 the t case is the problem you need a larger spline input to put the t case on to a 400.... what i would do is find a 400 trans and t case out of a 1 ton truck most came with a 400 and a np208 t case....i have done this many times it is a easy conversion i got a 400 and a 205 tcase in my garage all it needs is the adapter....

Are you interested in selling the 400? I'm sure advance adapters sells the needed adapter for the 205. Let me know if you'd sell the trans and what you want for it. Thanks

 

[anziconda]

Now now, the 700r4 was a great transmission, with the proper upgrades, it's hard to find a better over-drive tranny. Did you check the TV cable? how many miles are on it? Who was it built by?

It was built by Mountain Transmissions in Helena. The guy who runs the place won't return my calls. Yes I have checked the tv cable. The trans has approx. 15000 to 20000 miles on it. He told me that he put a bunch of upgrades in it to make it very strong...lol I guess not. If you know someone who builds a decent one, let me know...If the 400 conversion ends up costing too much I'd look into it. thanks

 

[coyoteman]

isn't the 350 and 400 a little higher geared in first? seems to me i tried a 350 in place of a 700 and it was geared too high in first gear, for what we do with our truck, but i am also running 273 gears, so i went back to the 700. they are a great tranny when built right.
i don't measure life of mine by miles, i go by years of service, it only gets used to chase coyotes, and all the miles are very hard.

 

[JET FUEL]

Don't bother puting a 400 in its not an upgrade. If you really wanted an upgrade look at a 4l80e swap. its alot of work to put one in and you have to buy a stand alone computer to run it, but you can only do so much to a 700r.

If you can rebuild it on your own they are cheap to rebuild, I just did one last week and had to replace a few hard parts, my cost on the rebuild was $400 bucks including a T/C and fluid.

 

[Motley Doo]

Look into a TCI or a B&M, they have all the upgrades done to them, are very reliable, and they stand behind them, on the other hand, if your buying one that doesn't require a core, go for a 4L80E and GM High Performance makes a stand-alone computer to be used in a carb car.

 

[justadude]

I'll tell ya what I do know about trani's















Gravler like them alot!!!!!!!

I have a 84 chevy 4x4 with a 700r4 auto trans in it. After a hard night of wheeling, its slipping pretty bad. Does anybody know if I could bolt a th-400 or a th-350 right in or do I need an adapter? This is the second 700r4 in 5 years and I getting convinced that they are overpriced pieces of schmidt!!! Any input is welcome...have to get the sled tote ready for winter.

 

[TBWdracula2003]

personally i would have it rebuilt with some heavy duty fibers and steels and while its apart put in a shift kit for more solid shifts

 

[justadude]

Come on, That there is an f'n classic!!!!

I'll tell ya what I do know about trani's















Gravler likes them a lot!!!!!!!

 

[AKSNOWRIDER]

It was built by Mountain Transmissions in Helena. The guy who runs the place won't return my calls. Yes I have checked the tv cable. The trans has approx. 15000 to 20000 miles on it. He told me that he put a bunch of upgrades in it to make it very strong...lol I guess not. If you know someone who builds a decent one, let me know...If the 400 conversion ends up costing too much I'd look into it. thanks

if built right..the 700 r4 is a good tranny..has way better ratios then the 400...as for a good one..go right down to your local gm dealers parts department and by a factory rebuild..they come with the latest upgrade parts...are built by gm and have a great warranty....make sure you set the tv cable right(is #1 reason they burn down),as well as flushing the cooler and lines good..otherwise build a good t-350 and redoo the driveshafts..if they are in good shape it should only cost you a little bit to get them redone...otherwise go find a 4L60e and the aftermarket makes a electric control box to run it on older cars..it will take the abuse and it will get both better performance and fuel economy....

 

[wildcard28]

Hello anziconda, my name is Darren and I have my own transmission shop in Clarkston WA That my father started in 1970 and went to work for him in 1988 and took it over 10 yrs ago. The 700R4 is can be built to be a good transmission even though there should never be an overdrive transmission put in a 4x4 pick up its easy for someone who has never been on the inside of a transmission to speculate on what they think is wrong with it, Shift Kit`d tranys are good but too hard of shifts cause friction and excessive heat, so you don`t want a teeth rattler when you feel a gear change. The killer in this trany is the TV cable most of the time is cause inproper adjustment or someone removed the quadrajet carburetor and installed a holly or edelbrock and but the tv cable in the same spot on the bottom of the carb thinking is the same as an older 350 trans which is totaly incorrect this is also a mistake when some one removes the throttle body injection to replace it with a carb too. theres a special bracket to be purchased to go on the aftermarket carbs to correct the geometry difference and the pull ratio on the tv cable the cable on the 3 spd trans if for passing gear (kickdown) and the cable on the 700r4 controls line and boost pressure effecting all the shift pattern. The 4th gear clutchs on 90percent of all the ones I have rebuilt have blackened or burned. another thing hard on this or any trans is Big Tires, if you running 273 gears thats way to high for a 3 or 4 speed trany in any hilly country especially when you tow sleds of car trailers.those gears should be only for flatlanders, especially if it is ran in overdrive position and dont put the trans in manual 1 when you initualy takeoff from a dead stop when you put it in manual one the low/rev clutchs engage in the back of the trans locking the center support to the center of the case and causing less stress on take off this also helps when on a hill when empty, A good cooler or one that is built like a radiator not a bunch of bent tubing looking ones are the heart of cooling.

To install a th400 is way to much of an interchange cost wise better off to buy one with already came with it
the th350 can be put in place of the 700R4, I have done many of these conversions, you have to modify the output shaft on a shortshaft 2wd trans and install a special aluminum adaptor on the back of the trans to take up the distance and put the transfercase back into the original spot and dont have to change the input shaft on the transfercase like the th400 was to be installed and other than the kickdown cable and filler tube with dipstick . its a good addition to reliability. I have a couple th350 trany`s in stock now for the 4x4 and could set you up with a good deal on building your trany By installing a good shift kit and recalibration kit (no B&M kits they have hard shift and dont help longivity). if you`d like to stay with the 700, or change to the 350.
Darren Card
Card`s Transmissions
wildcard28@msn.com
208-305-4732

 

[anziconda]

Wildcard, this is the deal. I have decided to stay with the 700r4. I need the conversionn for the tcc because I have eliminated the electronics for it. Mt. trans said he does it hydralically? I do have 33's for tires, but it has 4:10
gears, so it should handle it. Mt trans will sell me one for 750 and if you can match that I'd give you a try first. let me know.