MityMse

I did a search but couldn't find this problem. I have an 84 automatic and the last few weeks have had a shifting problem in the cold weather. Yes, it does get cold in Arizona, just not in Phoenix. Anyway, my commute is about seven miles and the car shifts ok as I'm leaving my driveway. About five miles later, however, I have to come to a stop at a stoplight. Then the trouble starts. The car revs very fast but it's like the transmission is not connected. I am going at a maximum of 40 and the engine is at 5000rpm. If I let off of the gas pedal, the rpms drop to normal idle speed. If I try to accelerate, I can maintain 40mph, in other words, I don't slow down but can not go any faster. For the next two miles the problem persists and I arrive at the office. In the afternoon whenever I leave it has warmed up so the problem does not reoccur until the next morning. Any had this problem or can give me a headsup?

Thanks in advance,

ZC Wilson

Jim bailey - 928 International

The brake bands in an automatic really do not tolerate slipping anytime the engine will rev to 5000 rpm and only go 40 mph there is serious amounts of slipping going on . The fluid in the trans will now be burnt , I would suggest a fluid change and HOPE it works . When ever an automatic exhibits this type of behavior it really should not be driven ,major damage can occur very quickly .

MityMse

Thanks, Jim. I will change the fluid asap. Any ideas as to the cause of the problem and what fluid would you recommend?

ZC

Jim bailey - 928 International

The autos use Dexron fluid ..... it might be low ? the automatic uses hydraulic pressure and a mechanical brain ( valve body ) centrifugal governor and pressure cylinders to do all their "magic" . Nearly everything is based on pressure which changes as things go from cold to hot .

SharkSkin

I second what Jim is saying.... IMHO, if any AT car slips like this, you should NOT drive it. Tow it, rent another car till you can get it resolved.... But it is in the process of self-destructing. Every inch/yard/mile you try to drive it reduces the chances that you can make things better by adding fluid, changing the filter, etc.

However, my experiences with American AT's is that if it slips like you describe at all, your friction surfaces will be glazed and it will never be right again. That's not to say that fluid/filter won't get you another few 10's of thousands of miles out of it, just that it won't be quite right. I can't believe that P-cars are significantly different in this respect.

Also, I'm not sure what kind of filter is on the 928 AT, but whatever it is you should change/clean it.

D

MityMse

Sharkskin, thanks also for the reply. But why would the transmission slip only under the circumstances that I originally addressed? No slippage when the outside temperature is 35+ and only after I have driven five miles or so whenever it is cold?

ZC

MityMse

Jim and Dave, would you recommend synthetic oil for the change? If so, which type?

ZC

SharkSkin

Pure guesswork here.... pressure/viscosity issue? Maybe something(any of a large number of possibilities) is marginal and it can't operate properly with the fluid hot/thin. The viscosity change is usually not enough to cause this by itself, or AT's wouldn't work in the first place! Something is already marginal. Minimum, do the fluid & filter change. It may get you a few more miles, a few thousand, or none. But it's cheap, relatively.

Sorry to be doom & gloom, but a slipping AT is no joke.

Usually, by the time you notice that your bands or discs are slipping, they are already glazed.

D

Steve Cattaneo

If you have a cold only shifting / slipping problem you have a sticking governor or valve in the valve body. Like others have said check your fluid and do not drive the car.

If you have the transmission power flushed that my clean the valves and free them. A valve will stick if it gets contaminated will metal from a transmission failing or metal from normal wear of the transmission. If you need to drive the car try shifting it manually.