Transmission crappy when hot...

[Fred 86 GN]

When the transmission in my 86 GN is cold, it shifts great -- nice and firm, at about what I would consider the right rpm, it downshifts well, and it shifts at part throttle/load well and at reasonable mph.

When it gets hot (warmed up) all that changes for worse. Shifts are soft (1-2 cannot be felt sometimes) 2-3 often has a stutter/flare, the WOT shifts are at about the right rpm, but part throttle shifts are WAY early. And the transmission will not kick-down to first at 10-15mph. Very annoying.

I have set the TV cable both to the stock position and one notch towards the firewall. I like the shift feel at the later position...that is until the transmission heats up!

The 200R4 supposedly has an Art Carr shift kit in it, a low-one activated transbrake, and a recent rebuild (or so said the previous owner). It hasn't been right since I have owned the car for the last six months.

I have only put about 250 miles on the car in that time.

Why would the transmission behave so poorly once it is warmed up???





Thanks,

 

[makurtz]

Sounds like line/tv pressure is dropping off as the trans warms-up & the fluid thins. Could be simple as miss-aligned valve body gaskets or pump hsng halfs causing a cross-leak or restriction when trans was rebuilt.

 

[MeanBuicks]

Do you have any idea how hot the transmission is getting?

Are you running a lock-up converter? auxiliary trans-cooler?

If the transmission is over-heating for some reason, it can act stupid.

 

[Fred 86 GN]

It has a stock lock-up converter and no auxillary cooler. I plan to get a cooler soon and would be happily surprised if that cured the problem...maybe worth trying before I have someone tear it apart.

Ran the car at the drag strip today. On the way there the transmission behaved O.K. Started to act a little bad right when I got there (30 mile drive).

Then the first run it felt like there was not 1-2 shift -- just one big mushy acceleration feeling as second gear slowly engaged. 2-3 was a big stutter and flare.

Second run the 1-2 was better, but the 2-3 was still a stutter/flare ordeal.

Third run both shifts were decent. Wonder if the transmission had cooled a little or if it is foaming if the foam had disappated???

On the drive home the transmission shifted very firm, and very early -- third gear by 30mph!

Any additional thoughts on what could be the tranmission's problem(s)??

Thanks,

 

[mr_85regal]

dont worry fred... i have a 85 N/A regal w/ the 3.8 2bbl and a TH350 trans. mine does the same.. at cold temps my shift points are 1st 50mph 2nd 85mph and i cant redline out my 3rd. but when the car is pampered drivin till warm they change to 1st 45 2nd 80 but when i get on it alot and drag em out it shifts at 1st 35.. 2nd at 65-70 and i hate that.instead of shiftin at 4100-4300 rpms cold it shifts 3600-3800 hot. i hate it also but the way i found around it is manually shifting 1st to 2nd. i think adding a trans cooler will help alot and prob a better shift kit.

 

[Crazi]

Three words......ADD A COOLER!!!!

You can kill your trans faster by overheaing it then by almost anything else. i have two on mine and am getting ready to look for a bigger one with a fan on it. You CAN NOT run a trans too cool (unless your are in alaska )

 

[FlyinGN]

let me ask a question Fred.. Please don't take offense...Why the HELL if you knew the trans is not right take the car to the strip?? You can hurt it even more and the times will be a dissapointment .. For the life of me I don't understand that ..

 

[Fred 86 GN]

If I waited until everything on the @*#%!! car was "right" before taking it to the strip, I would never race it!

I have owned the car since February. For four months of that time I got to pull the engine and do a complete rebuild myself -- my first ever. After getting it back together, and being surprised that it seems to work, I am terribly impatient about getting the @*#%!! car out to the drag strip and at least getting some baseline runs! You know...what I bought the car for!!

The transmission will probably need to be rebuilt or replaced...I already resigned myself to that before taking it to the drag strip. So why the HELL would I spend another $700-$1500 for the tranmission work without even knowing if the car is going to be worth my trouble? I will probably spend the money this winter. I want to play with the car for a while before then.

I am quite happy with the numbers the car ran at the strip (I was not disappointed, they were what I was hoping for), and know that when the transmission it "right", the car will pick up a few more tenths. Like I said earlier, when the car is cold, the transmission works great. So all is not completely messed up...

This is a play car for me. I simply want to run a few high 11's and be happy for a while. Making it perfect is not the plan for me...it has too many miles on it to try and make it a show car.

Thanks for your constructive input FlyinGN.

 

[mr_85regal]

just put a trans cooler on it and a shift kit. save ur money. after that it will be fine. i had the exact same prob.. after i put on a cooler and shift kit. there goes the hot trans. it runs now like it does when its cold..

 

[FlyinGN]

Originally posted by Fred 86 GN
If I waited until everything on the @*#%!! car was "right" before taking it to the strip, I would never race it!

I have owned the car since February. For four months of that time I got to pull the engine and do a complete rebuild myself -- my first ever. After getting it back together, and being surprised that it seems to work, I am terribly impatient about getting the @*#%!! car out to the drag strip and at least getting some baseline runs! You know...what I bought the car for!!

The transmission will probably need to be rebuilt or replaced...I already resigned myself to that before taking it to the drag strip. So why the HELL would I spend another $700-$1500 for the tranmission work without even knowing if the car is going to be worth my trouble? I will probably spend the money this winter. I want to play with the car for a while before then.

I am quite happy with the numbers the car ran at the strip (I was not disappointed, they were what I was hoping for), and know that when the transmission it "right", the car will pick up a few more tenths. Like I said earlier, when the car is cold, the transmission works great. So all is not completely messed up...

This is a play car for me. I simply want to run a few high 11's and be happy for a while. Making it perfect is not the plan for me...it has too many miles on it to try and make it a show car.

Thanks for your constructive input FlyinGN.

I said to you please don't take it wrong. Sorry. Was not meant to make ya mad.. my bad

 

[WE4]

Well..... I for two, are confused. I would have to ask why too. Why would you race something , as dollar consuming as the trans, if you knew you had a problem? You have to admit, it does sound a little odd. Have you cked line pressure yet? Might have been something as simple as cavitation, however, at this point , I'll bet money, you are starting over as you will find you have junk. All it takes is one big slip or flair to wound. Good Luck


Bruce
WE4
www.ptsnctb.com

 

[Fred 86 GN]

Trans cooler helped!

Thanks for the advice to install a transmission cooler! I put a B&M stacked-plate style (26,000 GVW) in the front-center lower part of the raditor/A/C condensor. So when the car is moving, it gets some air, and when it is not -- I turn on my 400cfm 7" Derule fan that is bolted to the cooler!

The transmission now shifts well and doesn't degrade with heat. There is still a flair on the 2-3 shift every so often, but the 1-2 is good and no more super short shifting. I am much happier.

Bruce -- I have one of your transmissions in mind when this one gives up the ghost. I was very impressed with the thoroughness of your "how to beef-up a 200R4" post. Do your complete transmissions for sale come with all those modifications?

I am amazed that a cooler made it much better.

 

[WE4]

yes we do.... and most are amazed at the difference the drop in temp makes. Heat kills....PERIOD!!!


Bruce
WE4
www.ptsnctb.com