I didn't "criticize" at all. I just stated a fact. It's a business decision on his part to buy low cost parts. As I said earlier, the shop owner told me they never had a complaint. They have been in business for over 40 years at the same location and it was started by the present owner's father. He has some knowledge of performance upgrades but his business is 99% "family" cars.

I live about a mile from the el cheapo trans part supplier and I have used them myself. It's a matter of making a decision on what quality you need. I went there to buy a governor cover because mine cracked when I pried it off. They only had used ones so I opted to go somewhere else. There is also a TranStar store about 10 miles from me and I will go there if I want quality parts.

I rebuilt this trans myself a couple of years ago. I used a kit from Dana at Pro-Built Automatics. It came with all the required seals and I used all new.

I have checked the flex plate for cracks and it is OK. The center hole fit was quite tight. I have seen recommendations to sand off the paint on the snout of the torque converter but I did not do that.

The Boss Hog torque converter I put in when I did the rebuild failed after 150 miles and I then put in an Edge torque converter. I used new torque converter bolts when I replaced it.

The pump came from Bow Tie Overdrives and has a 0.500" valve, so yes the pressures are higher than stock. It has the TransGo SK 700-Jr kit in it. I swapped in this pump because my trans started slipping when hot and I saw very low line pressure (less than 20 PSI in Drive when hot). I used a new gasket and seals. That's why I know the el cheapo place charges $20 for a seal kit -- I had to buy the whole kit to get the pump gasket and seals.

I'm about to leave for my lunch run and will stop at AutoZone to get some UV dye. According to their web site they have it in stock. I'm leaving tomorrow to go to an autocross and won't be able to get back to this until next week.

 

The dye didn't work for me. I put in one bottle, which apparently wasn't enough. I drive this car every day and every day there is a puddle about 2" - 3" in diameter on the garage floor. I bought the fancy yellow glasses and UV light made by the same people that make the dye. Can't see any UV glow in the puddles. I can see it on the dipstick, so it appears that the dye is not concentrated enough to see with small amounts of trans fluids.

I took a close look at the trans and the fluid is definitely running down the front of the pump. The only possible source is the front pump seal. I checked the pump bolts (all I could reach) and they are all tight.

So it appears that the only way to fix the leak is to pull the trans. I'll just put that off for a little while (maybe forever -- I really hate the job of pulling the trans), but it is irritating to have that puddle of ATF on the garage floor. At least it's no longer mixed with engine oil since I replaced the timing chain cover seal (gee -- they look VERY similar).

 

This has been an on going problem for me also. Every time I take the tranny out I put in a new seal then a couple weeks later it weeps after parking it. Can I drill this hole out without taking the pump out of tranny?

 

Have either of you "confirmed" that the case vent is operational? Plastic vent or metal-tube?

24202440 I believe is the later 4L60E metal tube

 

dang guys, your making me nervous. As you can see from my Avatar..I am just finishing up a tranny pull for this very reason. I hope it isn't an issue with these trannys.

 

If I can get my hand up to vent tube how would you check it? Blow some compressed air in? Tranny is in the car of course.

 

Funny you should mention that because I DID take the tube out and check that the hole was open when I rebuilt the trans. Since then I had the trans rebuilt professionally. I assume they dip everything in some kind of solvent tank, so the vent should be OK. I don't have ATF coming out of anywhere other than the pump (I checked), so i don't think there is unvented pressure. Wouldn't it vent through the dipstick tube? I think that would blow out ATF since the lower end is submerged.

I took the original trans out of my car about 10 years ago because the seal was leaking and had it rebuilt professionally. It started leaking immediately after I installed it (I took it out and put it back in myself). Years later, after getting tired of the puddle under my car I decided to do something about the leak and while thinking about it I remembered that a friend of mine swapped out the 700r4 in his '89 for a 6 speed ZF. He gave me his trans, which had multiple problems internally. I rebuilt it myself because I was unemployed and had little money but lots of time. It was fine (no leaks) for a couple of years and then failed mechanically (the front drum was cracked, which I think was probably done by the previous owner but finally got bad enough to cause problems). I had the trans rebuilt professionally and it started leaking from the front seal shortly thereafter.

So with my sample size of two, yes there is a problem with these transmissions. It seems to be a quality issue with the seals, as the original and the one I used in the rebuild lasted well. It was the cheap seals that leaked.

 

On the older style pumps sometimes the front bushing moves forward and pushes the seal out of the front of the pump. The "fix" for this is to use a seal retainer that keeps the seal from being pushed out.

Some people recommend drilling out the drainback passage to reduce the fluid pressure on the inside of the seal, which should help it to seal without leaking. The passage in question consists of two intersecting passages and one must be drilled out from the outside and the other must be drilled out from the inside. So the pump has to come out in order to do this modification. Here's a link that shows the modification:

http://www.crankshaftcoalition.com/w...ain_back_holes

In late 1987 a new version of the 700r4 went into production. The pump has a lip on the inside of the bore that keeps the bushing from moving forward. The bushing must be pressed into place from the inside because of this lip. They still use seal retainers on these transmissions. The later pumps already have the drainback passage enlarged, so I think that was part of the redesign.