Mazda 626 Needs Transmission help

A customer of mine who has me do most of the work on their Trailblazer brought a 93 Mazda 626 to me the other day. I went and did a check, Couldn’t even get it into the shop. They managed somehow to drive it in, but when I went to roll it around it would barely move. If you pressed the gas, nothing would happen until right after you let off. Then it would suddenly accelerate. They claim that it would do that in 1st gear and reverse (Automatic Trans), but once it shifted out of 1st, it would drive just fine. I’m not a trans mech, just a general shop. I think what most likely happened is that the 1st/reverse clutch went bad. If I remember right from my basic transmission course that it has either a band/transmission that could have gone bad. I don’t think that the torque converter is gone, and the fluid looks nice and clean so I doubted the trans filter. Any ideas? Am I on the right track?

I assume you checked that the fluid level is up to full hot. The next thing to check is the line pressure at idle in neutral, in drive, and in reverse. That should tell you if this is a pressure problem. If pressure is good, your customer is probably looking at a rebuild.

If the pressure is low or nonexistent, drop the pan; change the filter; make sure that the inlet seal is patent i.e. is sealing out air; inspect for debris; clean the pan; regasket; and refill. See if that solves anything.

In browsing, I came across the inspection procedure for the torque converter. In addition to the inspection of the stator one way clutch and the turbine axial play, there is a check of the oil pump drive socket inside the torque converter. The recommendation was to make sure that the pump shaft could be loaded to 10 ft/lbs of torque. If the manufacturers are specifying this check, there must be some substance to their concern. The difficulty is that transmission has to come out to do the test. Actually, the pump drive shaft could be slipping at either end. BTW is the transmission making any strange noise(s).

It is unlikely that the 1st/reverse clutch is bad because 1st reaction is taken on a one way roller clutch. The 1st/reverse multidisk clutch backs up the roller clutch for manual 1st. BTW I assume you have tried the transmission in manual Low.

Hoper this helps.

No, the transmission isn’t making any strange noises, and I did check the fluid levels at full hot. There are small pieces that appear to be dark brown, almost too small to see in the fluid. It’s not burned though, the fluid I mean. This is after my cursory check the other day. I couldn’t see them in the lower light of my shop. Once the car gets out of first gear though, it seems to have almost no problems.

A line pressure check might point toward some problem in the valve body. At this point a pan drop, filter change, valve body inspection, and air pressure checks of the forward clutch, 1st/reverse reaction clutch, and reverse clutch is about the only service/inspection that could be done without having to remove the transmission.

If you find out what the problem is, please post back to give us the answer to this puzzler.

Good luck on this.