89 gmc 3500 6.2L 4X4 auto the truck has a turbo 400 in it right now, I'm looking at putting a 700R4 in, I know this is a weaker tranny, but I drive the truck 95% with out a trailer on and with no load, (a everyday driver) my question is will any 700r4 work? I know it has to be a 4x4 tranny, I have a 700 out of a 89 4x4 S-10 4.3L ......will it work? the only thing i can think of that I need is the bracket at the injection pump for the cable...





any help?





Skippie

imo I think you will smoke a 700r4 just my 2 cents

a properly built 700 will do very well. I would get one of the later versions to use, your 89 should be fine. If it has the secondary valve body in it, its a good one, the input shaft on them is larger as well. Build it stout, and put in a Transgo correction kit and it will serve you well.

Not to contradict dmax, but if I were in your shoes, I would scroung up a 4L80.


Never found anyone who would build a 700R4 to last more than 100K. I am not a big fan of it.

I 700R4 will live behind a 6.2 with no problems at all. Do not give is a second thought. Just make sure that you get a 87 or later 700R4 and it has all of the lastest factory mods. You will need to get a low stall torque converter though as stock gasser converter will be too loose for it at lower RPM's. You want about a 1400 RPM stall or so. Also, install a after market aux tranny cooler too and I cosider it a must have with any SUV/Truck. A 6.2 makes no more torque than a 350 and 700R4's handle them fine and I have seen some use them behind mild big blocks with success too. The 700R4 got a bad rap because there were some design issues until 87 and the 81 through 84's where very troublesome too. Also if you obtain a older 700R4 and rebuilt it, it is fully upgradable to the latest version without any specail effort. I have a 700R4 ui a 89 gasser burb with 170k that I bought new and it still works like new.

Also you must consider that the 700R4 has a 3.06 to 1 first gear vs the THM 400's 2.48 which will give you a lot more startout torque. Second gear is also deeper 1.6 vs 1.48 for THM400 for better mid range too. I think you would be quite pleased with the results. Edited by: snoman

Thanks guys,





I must say I'm omost excited to see what that overdrive gear does for my fuel milage,my truck has no tach, but I know the truck has 4:10's with 285's must be turning dam close to 3000 at 55mph, I'm definetly doing the swap, hopefully with in a week or so, my only concern now, and I must thank Snowman for bringing up, is what is the stock converter in a 89 S-10 4x4??? I know in the 2.8L 4x4 they where 2500...


That 3.06 first gear is exciting too, can't wait to pull my trailer,


Skippie

you will need a converter for a diesel to put in it, they are different.


A 4l80E will require a computer to shift it, a 700 will work without, but a good choice though

Skippie,


Not to talk too much about past trucks but... I had an 87 K5 Blazer, 14 bolt in the rear, dana 60 up front 205 tcase and a 700r4 built by Darrel Young, he is in the San Fernando Valley in CA. He built the tranny to hold up to a 454 with 400hp. I never got the money to put the big block in it and used a 300hp 350 but that tranny held up extremely well. I have alot of faith in that tranny from the abuse I put it through on and off road. You'll love the overdrive and the low first gear compared to the t400. I don't know if they are different but try to get one from a full size truck. Hope it helps.


LA DMAX

you will need a converter for a diesel to put in it, they are different.


A 4l80E will require a computer to shift it, a 700 will work without, but a good choice though








My bad...forgot that part.http://www.dieselplace.com/forum/smileys/Embarrased.gif

you will need a converter for a diesel to put in it, they are different.


A 4l80E will require a computer to shift it, a 700 will work without, but a good choice though

I would not even consider a 4L80 as it is not at all needed here as the power capacity of the other trannies is more than enough for this task. It would be a 700R4 or a 4L60 as both have a 3.06 first gear while the 4L80 has a 2.48 first gear like the the THM400.

Thanks guys,





I must say I'm omost excited to see what that overdrive gear does for my fuel milage,my truck has no tach, but I know the truck has 4:10's with 285's must be turning dam close to 3000 at 55mph, I'm definetly doing the swap, hopefully with in a week or so, my only concern now, and I must thank Snowman for bringing up, is what is the stock converter in a 89 S-10 4x4??? I know in the 2.8L 4x4 they where 2500...


That 3.06 first gear is exciting too, can't wait to pull my trailer,


Skippie


I would put your 60MPH RPM at around 2700 in current configuration. You MUST get a low stall converter though for a V8 or diesel though for it as a stock converter from a 2.8 would stall a lot higher still on the engine and yeild very poor performance. The correct converter will make or break this swaps performance. You need a stall of around 1600 RPM or so max for this to work correctly. It a pinch a torque converter from a big block will work for you in this application as it will be "tighter" than one from a stock small block.

Don't forget to wire the solenoid for the lock up clutch. Not having the clutch working properly will put the converter in melt down the first time you pull a big grade.


mike

I would put the Gil Younger kit (Part# SK 700-D) in it myself, I had one put in (behind a 6.2) and did a hell of a job. Puts more pressure to the 3rd and 4th clutch pack, 700r4's weak spot.

all in all, lots you can do to a 700 and make it handle all a 6.2 will throw at it. Trans go stuff and a sonnax sure cure kit or whatever...

all in all, lots you can do to a 700 and make it handle all a 6.2 will throw at it. Trans go stuff and a sonnax sure cure kit or whatever...

It will handle it stock without any problems at all it just has to have correct converter. I have seen stock 700R4's live long lifes behind more powerful engines.

thats very true, but if your gonna o/haul it, you might as well do it right IMO

The "weakness" of any 700R4 is heat. If it is not properly cooled with a aux cooler, it will fail or have a short life in heavy use. Keep it cool and it will take considerable abuse.