in transmissions between 87 and 88-92 700-r4's ????

no one can seem to answer me yet when shops rebuild these they ask for 88+ any reason why?

 

I think the accumulator pistons received O-ring seals. It is a common upgrade for the earlier 700R4's

 

what would make a difference though when looking to rebuild.......


in otherwords if you were to use a 87 and an 88 and put in the same parts to rebuild would there be a difference??

 

Well I think the difference would be in the rebuild kit and the type of seals that come in the kit. However, if you were to upgrade an 87 with the later seals, there would be no difference.

Did you ask the tranny forum?

I'm by no means an expert on trannys so I'm not even 100% sure.

 

yep no replies.........


i have a rebuilt 91 i'm thinking about trading a friend for his 87 that needs to be rebuilt. just want to make sure i'm not screwing myself.

 

I'd stick with the 91 you already have IMO. the 89-up ones are the best ones.

Is the trade an even swap or are you getting some $$ if you do it?

Unless you're getting cash with the 87 tranny, I'd stick with what you have.

 

understand that i'm getting money obviously since mine works perfect and i'm getting the 87 so that i can build it.

i need one with stronger parts for more power.........



all i want to know is if there is a difference if i were to build the two.


side by side, can they be built the same for the same price or are there differences that make one cost more than the other or keep it from being as strong.


does anyone know????

 

In that case, there is no difference.

If you have either one built up for performance use, both would receive the same components and upgrades to sustain the power.

The 87 would probably cost a little more due to it being upgraded with the better accumulator seals. However, I don't think it would be a substantial difference.

 

I would also stick with the newer one....I think your '91 might have electronic controls, where as the '87 most likely doesn't. I would also try asking it on the tranny board...those guys are incredible.

 

yeah all i knew was that their was a different, now i know....

 

everything electronic can be switched....


does anyone know if there is a real difference.


if i pulled both from a junkyard with plans of building the same identical unit which would be better and why?

all anyone says is the 88-92 is better. stock i understand; but if you have to rebuild anyway what is the difference?

 

Kandied91z, I have all the information that you need. These are all the differences year by year as taken from the GM Hydramatic 4L60/4L60E product Update book. The book is a GM Tech Guide that lets you know the upgrades year by year and what will work with newer and older models, also the build dates that changes happened. Its filled with pictures and part numbers. Most of the changes are product upgrades or shift feel upgrades and when performaing a rebuild you would be upgrading them or recalibrating the tranny to your performance needs. Somethings will not come in a rebuild kit and can be upgraded by purchasing and installing yourself. Most of the major changes happened in 87. Just remeber the changes happened during 87 so not all 87's have the new parts and case but by 88 they do. I think most places just ask if its an 88 or newer because it makes things easy. half of 87 is the old style case and parts and half is the new style with auxiliary valve body. You need to know what your (Julian production date) of the 87 tranny to know if you have the new or old style.

87 production year
Torque Converter Clutch temperature Switch Added
Orifice Cup Plug Added to the Rear of the case
Electronic speed sensor added
New sprag assembly-Forward clutch to overrun clutch hub
New overrun clutch hub
Shft recalibration
Auxiliary Valve Body assembly added
Forward clutch checkball added, Lo reverse checkball removed
Double orifice checkball added to case
New spacer plate
new spacer plate gaskets
deeper oil pan
solid turbine shaft seals
input housing turbine shaft
case change, forward clutch feed hole eliminated
oil pump cover-forward clutch feed hole
larger feed hole oil pump cover
reverse input clutch housing
reverse input clutch packs
revers input clutch pistons
selective reverse input backing plates
lo/reverse clutch piston
lo/reverse clutch pack
selective lo/reverse backing plate
input clutch housing and shaft assembly
forward clutch backing plate
third/fourth apply package
third/fourth clutch selective plate
2/4 servo apply piston pin seals removed
new 2/4 servo pin selection

88 changes

New control valve assembly
new input clutch assembly with 3-4 boost springs
reverse input clutch piston
case change-slot lo/reverse case hub
governor driven gear
solenoid assembly wiring

89 changes

control valve assembly
3-4 throttle valve/sleeve
spacer plate
piston seals

90 changes

lo/reverse clutch support
2-4 band change
forward and 3/4 clutches

91 changes

1-2 accumulator calibration
3/4 clutch plates
output shaft and seals
lo/reverse clutch
2-4 servo cushion springs and spacer plate

92 change

TV Limit Line-Up

Let me know if you need any more info or the Julian production dates of changes.
Extreme

 

thanks, i sent you a pm!

 

I just PMed you back but your mailbox is full, empty it out and let me know.
Kevin

 

The main reason that myself and most other tranny builders look for '88 and later cores, is because, although 1987 was the "new style" case, using the auxilary valvebody and a host of other improvements, it still used the "old" style valvebody, so I consider it an "imbred" 700R-4. You have to build it up as though its a later style, using things like an '87 and later input housing, etc... but you have to do valvebody work like its an '86, which includes installing the TransGo. I'd rather just not deal with it, but I'll work on it if I have to. As far as strength goes, its negligable. Its probably just as strong.

 

87 and 88 would be equal in strength. The 88 transmissions have no new strength upgrades from 87. I agree that the 88 has a better valve body for stock applications but offers no strength increase over an 87. I find that when rebuilding either 87 or 88 the valve body dosen't play a major role in selection because you will be recalibrating either one for new shift feel. I know we all have opinions but can agree that the 2nd desighn 87's and up are much better transmissions then the 1st desighn 87's and down.
Extreme

 

how do you tell the difference in 87??

 

check your PM's. for 87 you can tell the difference between the new style case and old style three ways. First the pan is .040 deeper then the old pan for auxiliary valve body clearance. The indents around the magnet are smaller to identify the new pan. You need to know what the older pan looks like to compare. Remember the pan can be swaped and was a gm replacment part for all years and GM started using them before the auxiliary valve body so you never know. Also like you would notice a .040 increase in depth but i just thought I would let you know. You could drop the pan and look for the auxiliary valve body, makes a mess or check the production code on the side of the block. You need a Julian Production date of 279 (October 6th 1986) for 87 model cars. We all know GM and that Production date codes and records are off. The best way is to remove the pan to be 100% or have a production date thats not close to the change over date. Also don't forget a Julian date of 028 would be (January 28th 1987) and would be a newer tranny then 279 but have a smaller number.
Extreme

 

thanks alot for all your help as you really seem to know your stuff on these parts....although with that long list of cars below i can see why!