vinny R

So I have been having a trans issue. 700R4, I have never encountered this problem in any of the autos I have owned. When the trans shifts under load the car sways to the right, the more power behind the shift the more the sway. It has the weight shift feeling of the car breaking lose. The shifts feel heavy and more slides into the next gear instead of a fast, crisp shift. I have adjusted the TV cable and it made a difference for a minute. About a couple months back I checked the fluid and it was over full. I pulled over a qt. out and with the engine hot idling in park the fluid level was good and the car did shift better, but progressively went back to the problem. I drove it last night and it was bad, the shifting weight of the car made it feel like I was going sideways, it's a weird feeling, like the rear end is sliding out. So I checked the level and it was high, over the bend in the dipstick and it had air bubbles on the dipstick. The fluid looked thin and very light colored and could hardly tell where it was on the stick. I shut it off let it sit for a minute started it up and rechecked. Still high. Below is a pic of the fluid on the stick. The level went down some and the bubbles are gone after letting it sit but as you see the fluid looks watered down.



Could an overfilled trans cause this weight transfer, sliding out feeling? It also is strange that the fluid is this high on the stick as I haven't added any since I removed fluid and set the level. I had the trans serviced about 7 yrs ago and this problem started about a year ago. No fluid has been added so could it have been overfilled ever since and all the yrs of driving overfilled cooked the trans. I am sure I checked it periodically over this time. I have not seen trans fluid this watered down looking before. Burnt or old fluid looks and smell different. It does not slip and when you put it in gear it drops firmly into drive and reverse.
I was thinking of having it serviced again but the unusually high level, bubbles and color makes me think it could be something more serious.
Any opinions on this appreciated.

Aaron R.

Sounds like you need to change the fluid and check the rear transmission mount.

Roorancher

I would do a complete fluid and filter change, and check all your suspension components and mounts....motor mounts, transmission mount, torque arm, shocks, spring upper donut, panhard bar, bump stops, etc. Even U joints could conceivably contribute to a problem. Wouldn't hurt to pull the cover off the rear end and inspect it as well.

vinny R

The rear suspension is all new or within the last 4 years and maybe 6K. I just lowered the rear 6 months back and had the trans mount and torque arm bushing replaced at that time, used the black urethane. The problem existed before these parts were changed and the rear lowered, I was hoping that these bushings solved the problem. I have all urethane bushings in the rear and Founders Performance trailing arms, Panhard bar and LCARB's. I used lowering springs and the isolators were good and still intact. I can safely say the suspension is tight.
I will make appointment with my local trans guy and have him do the service and let you know if it fixes it. I just have this feeling that this problem is not going to be resolved by a fluid swap but I hope I am wrong!

Roorancher

If you were in Texas, I'd send you somewhere that may help Transmission-wise.....but I guess you could call them or email them and have a conversation and pick their brain. I've had 3 transmissions from them over the years, and called many times for advice. They're very knowledgeable, and ship transmissions all over the world.

www.phoenixtrans.com.

vinny R

Thanks RooRancher. I called my guy here in town and gonna take the car to him next week. He wants to go for a test drive before he does anything. This guy has been doing working on transnissions in this town since the mid 80"s so he must be doing something right.

HelenJohnson

Any update?

vinny R

yeah, I took it by the shop and of course on the test drive it shifted normal. He looked at the fluid, smelled it and said it looked good and didn't see the need for a change. He told me to bring it by the next time it is acting up and we will go for another test drive. He did kinda baby it on the test drive. The car temp was up to 180 and I had driven about 7 miles before I showed up.
The problem seems to happen after the car has been driven a few miles, you keep in the gas during a shift and the engine temp is up to 190-200. I may have to take an afternoon off and drive the car for a few to get it to act up and then go by for another test drive.

vinny R

Update to this thread, my issue is found, I think.

Below is a pic of the rear end housing. I had a leaking axle seal and had a mobile mechanic come by to replace both seals. While he was in there he noticed a broken bolt. That bolt is one of the four that hold the carrier in place. It seems that when power was applied the whole posi unit was moving in the housing. He was able to move the whole carrier by hand.I believe this is the cause of the car feeling like it was breaking lose and the weight shift. He was surprised I did not hear it, I felt it. When the top was up I did hear a "whine" coming from the rear end and that must have been the pinion to ring gear as it must have been off with the carrier being not secure. Needless to say the carrier bearings are shot.



The stamping on the end of the pinon gear, is that the ratio and is it 3:42?

Thanks