Hello,

I have an 86 IROC with a L98 out of a Vette and a shot 700R4 Transmission I wasn't intending on replacing when I bought the car a month ago. I am picking up a $75 core 700R4 that came from and 1988 Vehicle. My plan is to rebuild that and then swap it in. I also have a TCI 2400-2600 12in converter although not ideal, free that will be swapped in also. I am thinking of purchasing a rebuild kit from Probuilt Transmissions. Car will never make more than 350HP so big HP is not a concern. I can't afford to spend $2K on a new trans or I would. I would like to rebuild it at home myself. I am an automotive background, but I haven't rebuilt a transmission since College about 7 years ago. I remember it being a complicated PITA, however we managed to get it together without any problems. Recently i began reading online. I don't remember there being any transmission Voodoo in building one; i thought it was straight forward, however the more I read the more I feel like I am getting in over my head.

What are you thoughts?
Are any additional tools necessary or can i get away with my dealership wrenches?
Tips?

DG

 

Well, although there seems to be little interest in this thread I have decided to move fourth. I have a 700R4 out of an 87 Vehicle am going to forge ahead... just waiting for Dana from probuilt to give me a call back.

Dan

 

not necessarily lack of interest.

I'm not one who likes to drop a tranny and then slap in someone's used tranny. Around here, if you don't need hard parts, you can get a 700 or 4L60 rebuilt for $400. If you need a sprag or sunshell it's just the cost of that part beyond the $400. At those prices I don't mess with a tranny.

If you don't have $400, then slapping in an unknown is your best solution and say a prayer every day that it works.

 

With the horsepower you are putting out the HD rebuild kit should be ok. If you manually shift it a lot, then the Street/Strip build kit would be better. The TCI torque converter do not have a good history on the 700R4's, but for free I guess you could take a chance. The DVD comes at no cost with the kit. The ATSG build book is what would be needed here, or if you already have the Haynes manual, that will do.

 

It was a TCI converter that blew it's thrust bearing and
contaminated my tranny last year-it did have over
80,000 mi on it,but looks like the washers the thrust
bearing rollers rode against started to pit and flake
from fatigue then came apart-glad i had an extra
strainer in my cooler circuit as that caught a lot of the
debris!

 

That's too bad.. The converter was only used for 10 miles, and it was free. I guess i will have to look around for a used edge.

I don't know where you are from but here in NY, you'd be lucky to have a Tranny service done for $400, and that's no joke, never mind rebuild one with parts for that price.

I am going to "have fun with this car." I am not going to race it with slicks, but I am going to run it on the street, do burnouts and so forth. I would love to pay someone $2000 to do it right but the car isn't worth $2000. My hope is that If I can actually get it together and it works it will hold up longer than a stock used core would. I would hate to swap transmissions once more, only to find out the next one is slipping to.

DG

 

I'd still use that TCI converter if it looks good-mine
lasted 80,000 mi before it blew-also thinking back,
i remember when i got it the box was beat up pretty
good so it is possible the thrust bearing was damaged
by the converter elements knocking around in shipping.
I actually have had very good luck with my "junkyard"
700r4-i got it out of an '85 caprice for $150 back in '95
-i just looked it over,clapped in a transgo shift kit,and
ran it-over the last 15+yrs did some nasty things to
it(some by mistake)but it has been tough-gave me
new respect for the 700r4
when i had the tranny apart to muck out the debris
from the converter failure,everything still looked
good-basicly just put it back together and reinstalled

 

the street/strip rebuild of my 4L60E in my 95Z was $1600 and that was a bench job, not r+r so yes, I knew I had a good deal with the $400 freshening up of a tranny that was working good.

 

snap ring pliers, a pick, and a long magnet definetly help. and an accurately calibrated torque wrench. home made bushing drivers, feeler gauges, maybe a digital camera. the haynes manual for the 700r4 helped me out a ton.

just dont expect it to go together in a weekend, take your time and do it right. it definetly pays off. if something doesnt look right, or looks broken, ask and replace if necessary. dont skimp... you can build it yourself for less then 400 for just a basic rebuild kit and a shift kit. if you rebuild the core tranny from the 88, youll have the upgraded internals already.

edit, noticed you said 87 tranny in a later post. if you have the latter half of the 87 tranny, then youll have the upgrades. the older half do not have the cross over tube or aux valve body

 

The only difference between the early and late 1987 was the valve body and the separator plate. The early used type one valve bodies, and the late used the type two style. Internally everything else was the same. If you do decide to use a TransGo Performance Shift kit, then you must use a type two valve body when using the TransGo Performance Shift kit, otherwise some strange problems can develop when using type one.

 

pulling a 700r4, cleaning and rebuilding, and back in the truck takes about 10 hours. and that is going all the way thru it. now if you want the case cleaned, pump rebuild, and every other trick we have done them in 2 days.