JrRifleCoach

Been a long uphill road. Trans has been out 3 times,now going on four. I've learned a lot about troubleshooting automatics. Something that one would be happy to avoid. The toughest part is the expense of learning.

First, not using a business that has a warranty or guarantee has its drawbacks. I choose to use a neighbor who day job for the past 35 years is rebuilding transmissions. The first time through in 2004, the rebuild was perfect and never missed a tick until it started leaking at 45,000 miles. We opened it up for an inspection and found some slightly burnt 3rd gear bands and a broken pressure plate. We decided to rebuild.

After talking to the folks at Superior Transmissions (http://www.superior-transmission.com) and using a preferred vendor of theirs in Sacramento, the parts were purchased from PDQ. The trans was assembled and discovered the pump was that for a L60 not an R4. The parts rep was sure these were interchangeable. They are not! He also did not include the steels with the clutch plates. Another trip to Sac for parts. Since the WOT 2-3 shift was always "loose", the valve body was sent off to ValveBodyPros in San Jose for overhaul as well.

During assembly, we added a new flex-plate from Scat. Very well constructed and black powdered coated. This would be a problem later. The trans slid in and four hours later we topped of the fluid for a startup. I engaged OD/4th and let the trans go though the gears. Later I learned that some shops will leave the shifter disconnected and start in reverse. This will suck fluid from the pan thru the fliter to purge the trans and converter. In all other gears fluid is pumped thru the oil cooler first. All appeared OK and the TV cable adjustment was confirmed for the first ride.

Bummer. The trans was very late upshifting so I pulled up two notches from base on the TV cable. Still not enough pressure. Three more clicks and she shifted OK from 1-2-3-4. Once warmed up it became apparent there was a lot of slippage and no noticeable engagement of the TC lockup. I setup pressure gauges on the main pressure port and 2nd gear. Although pressures were within tolerance, they were at the low end. Most noticeable was reverse pressure. It recorded 40 instead of 70psi. A decision was made to pull and inspect the pump and clutches. We also discovered all the bolts attaching the TC to the flex-plate and crankshaft were finger tight. Powder coat paint is thick and disintegrated under the bolt heads and opposing side of the plate. The TC showed blistered paint on the surface between the bolt lugs. On the opposite inside is clutch surface for the TC lockup. Guess it really never locked up.

Again we opened the trans and again nothing of note was discovered. Reassembly included a new pump, TC and flex-plate. Same procedure for topping fluid and another road test. This time the TV cable required no adjustment from initial. However OD/4th was non existent until it reached 30-40 mph. No forward motion was attained by OD position . I started in D and shifted to OD at 30-40 and all was fine until I came to a stop. Then OD acts as another neutral.

Main pressure is on the high side of the curves and reverse is 72psi. Checking the forums and talking to a few local trans shops indicate the sprague clutch has been installed backwards. Next week I'll pull the trans again for inspection.

Lemme

Sounds like you are getting great experience on the trans.

I don't feel quite so bad now about spending $3500 to get mine sorted by my club mechanic when I lost 3 and 4.

Cliff Harris

The 4L60 pump is the same one that was used in 700r4s starting in late 1987. These 700r4s have an auxiliary valve body and there is a tube that runs from the pump to the auxiliary valve body. In 700r4s before 1988 you plug the hole in the pump for that tube. The later pumps have more vanes and give more volume and less pump noise.

Do you have an enlarged boost valve in your pump to increase the line pressure? If you don't, you should. It helps the clutches clamp tighter and prevents slippage. It is VERY common for 700r4 3-4 clutches to slip and burn.

383vett

I feel for you. I went through a number of 700R4s and a number of different builders when my car was a street strip car. When I finally got a tranny that would hold horsepower, I had difficulty dialing in shift points. I wanted it to shift at a certain rpm at the strip, and also needed good street shifting. I spent a lot of time playing with the governor; grinding weights, changing springs, even brazing weights to make them heavier. Finally, I bought a 4l60e, had it built and now dial the shiftpoints in on the laptop. Hope you get yours figured out. If you need a good builder, I finally found one. Shucks Transmission in Dublin. Jeff Gillette runs the place and is a current Top Dragster champ and knows his stuff. Willie

Jim McCombe

I agree with Willie, I also have one of Jeff Gillette's 700R4 transmissions in my 87 and very pleased with the workmanship and the efficiency of the unit. They stand behind their work and their service is excellent.
He can be reached at 925-828-9699

You will not be disappointed

383vett

See you Monday, Jim. The Wally is mine.

Tom400CFI

Recently, a friend of mine told me about problems he was having with his '05 BMW X5 (60k miles, no towing). Turned out the auto trans was bad. Dealer replaced the trans and TC. Bill was $13,000. My response was: "That is precisely why I will never own a vehicle like that." (BMW/Audi/Mercedes, etc). Reading your thread, all I could think to myself was...And this is precisely why zero out of the 4 vehicles that I own, have automatics. I hate 'em. A stick is easy to diagnose, and extremely reliable in the first place.

Seems like you're making progress though...maybe. And the others are right that you're certainly learning a lot, which never hurts. Hope that you get it licked soon!

Tom400CFI

Ha ha...if I didn't know better, I'd think that you were trying to tune a snowmobile clutch in this post!

ch@0s

Sorry to hear about it brother. GL
I think I may have fried my 4L60E running it low... I feel your pain.

383vett

Ship your snowmobile out here Tom. I'll give it a try. If you get it here in time, I'll run it down the strip tomorrow. It'll win it's class (only entry).

John A. Marker

Jeff at Schuck's in Dublin has built several transmissions for me over the years and has always produced a great product. His transmission is what is currently running in my 85.

tachout

The trans is out in my Convertible. I have checked around with several different shops, asking all kinds of questions, and with my skill and abilities, I have decided that it is going to a shop, rather than me going inside an automatic. It would end up costing me more to get mine out, apart, and replace what is bad, and put it back together, than just dropping the car off and having it done.... and behind that I end up with a warranty. The goal is to get it in shortly (In the next month or so) and having it taken care of. Good Luck with yours, and I will keep following this post.

Tom400CFI

LOL...I've always wanted to do that, especially back when I lived in UT, close to RMR. Never bought the slick track or the roller "skis" though, so never got to try it. It's a little red in the neck... but it's a cheap, easy way to go 9's or 10's. in the 1/4.

95BLKVette

I rebuilt my 4L60E about 5 winters ago after getting tired of being ripped off by the local tranny shops. Put in all custom performance parts, expecially the beast shell, hardened insput shaft and some 80E parts as well as high performance frictions and kolene steels.

I had mine in and out twice before it worked right.....used the 95 service manual, purchased both the 4L60E Transmission Manual and also a very good rebuild video. My greatest help was taking pictures and checking things with a forum member tranny guru...he actually let me know I had some of the roller bearings in backwards.

BTW, the forward sprag is a typical mistake and the video is very specific about how it gets installed.


Nice to gear someone else has been down this road too

Hang in there, sounds like you'll have a big smile on your face soon

JrRifleCoach

Amazing how much we learn after getting bit.
Early R4 pumps are not interchangeable with L60
How easily the sprague can be installed backwards.
I'm feeling lucky, I could have lost another $1k in parts.
And many recommendations for trustworthy shops a few hours away.

This extra day off gave me time to take care of other Honey-Do's, so the trans comes out tomorrow and off to the local shop for a teardown and inspection of the sprague. If its damaged probably haul it down to the valley or Dublin.

I gotta get this thing running for our fall run over the passes come the first Sat in October.

JrRifleCoach

Ok the news is good, so far.

Turns out, as Cliff Harris clearly pointed out, I was sold a late model R4 pump that wasn't plugged for an extra tube the early 700's don't have. Thanks Cliff! When we were checking the sprague clutch and discovered it was installed correctly, I popped this thread up on the shop computer as reference. Hole plugged, trans to be installed this weekend.



Once again this board and its members have helped to resolve yet another Corvette crisis!

ch@0s

Wow! learn something new everyday.. Makes you appreciate the knowledgeable members like Cliff.

JrRifleCoach

Cliff Harris

That filter O-ring shouldn't be in there... ;-)

JrRifleCoach

Gotcha

Goes back in tomorrow.
Got my fingers crossed