I have a '91 Z with a L98 and 700r4. Mainly in third... when you are driving and let off of the gas the RPM's drop all the way down to idle, and when you hit the gas again the engine speed has to climb all the way back up before the car starts pulling again. The car has 140,000 miles on it but otherwise runs great. I even took it to the dragstrip ( which is 2.5 hrs. away) ran six times and drove home still with no other problems. I haven't changed the filter yet but I just wanted to run it past you guys as this is my first 700r4 as well as first f-body.

 

This is while the transmission is in third and the shifter is in O/D? Sounds normal to me.

 

In third gear thats not normal. In third gear it should STILL feel as if its in gear, like a manual in 3rd gear. Engine speed should stay up because of engine braking. You should feel the car slow down as engine drag slows the car down.

If it feels like the transmission drops into neutral then something isn't quite right.

I'll have to dig up the old trouble shooting chart, doesn't tell you everything, but its pretty damn good.

This may help you. Though I don't think it contains the information to help you figure out your problem.
http://sethirdgen.org/tranny.htm

 

Mine has and always has had no engine breaking in 1-D, but does in OD... so doesn't seem that out of the ordinary to me. If you start having that issue in OD then something is up...

 

Ha, did you hear a big clunk before at any point? My trans does the exact same thing!! You most likely broke the part in the trans that holds the engine speed(kinda like a trans brake for downshifting and such) Could be like the piston or band? I am no tranny expert, but thats what I was told by a buddy.

 

If he killed the band he would have lost 2nd and 4th gear. I should know, I killed mine.

 

You could be very right. I honestly don't know exactly what causes the failure?? Either way something is wrong cause my trans is doing the exact same thing!! Any extra info would be great!!

 

In third gear with the selector in overdrive it is normal. The overrun clutch allows engine braking when the transmission is in manual third or below.

 

My bad, when he said third, I assumed the selector was in D, and not OD.

 

If you have "no engine braking" when letting off the gas in the "D" position, then most likely the overrun assembly is the problem. Worn out overrun clutches, the sprag itself is gone, the overrun hub is broken, the overrun piston seals are gone, broken overrun piston, any of these can cause this problem. This requires the diassembly of the transmission to fix this.

 

Thanks for the reply!! I am about to order a TC (Vig) from you, I was wondering if you have a problem shipping to Canada?

 

No problem, it will be dropped shipped to you directly from Precision Industries.

 

That's great, thanks!

 

Thanks alot for the replies. I guess I am gonna have to call a friend and get the tranny from his crashed TA. LOL, with 140,000 miles I figured I would have to rebuild or replace it, I had hoped I wouldn't have to. Oh well, I really appreciate the info.

Chad

 

LOL... guess this shows how much I know about trannys!!!

Yeah... now that I really think about it, mine didn't always not brake in D... LoL... so thats what that clunk was about 2 years ago!!!

 

Its not the fact that you don't know anything about them Chris. Its just that Dana knows sooo much more.......

 

Prolly why I will be getting a Probuilt when mine decides to bit the dust!!!