Transmission Issue (maybe)?

[B250]

I've got a B250 with an A500 tranny. It ran great until a few days ago, when I changed the ATF and adjusted the brake band (again, routine service). Strange things started happening afterwards. When I drove up a gentle hill there was a slight judder from the steering wheel for a few seconds (like driving over a rumble strip). I didn't think this was tranny related, but when I switched the overdrive off it didn't happen, although this could have been because of the change in rpm of the engine.

The front end judder seems to be random, but always starts when just going up a slight hill on the highway, other times it drives perfectly. This made me think it was an electrical problem (bad connection, etc) rather than a mechanical one in the tranny, or even wear in the front end bushes.

If I switch the overdrive off, it drives fine up and down hills

Today, though, the tranny seems to shift quickly (less than 1 second) from 2nd to 3rd. Otherwise it's OK apart from the occasional judder at the front end when using overdrive.

When I check the fluid level, the manual says to run the engine in neutral. When I do this one side of the dipstick is higher than the other! Putting the tranny in park gives a dispstick reading that is OK and the same on both sides of the dipstick

I also wondered if anyone had replaced their A500 with one of the manual transmissions. I assume the factory would make them physically compatible for cost reasons, although a clutch pedal/ hydraulic system would be required this isn't too difficult a project

 

[1970Pelle]

I think what you are feeling it is Torque Convertor Shudder. Do you have a scan tool to look at the convertor to see what its doing during the condition. I doudt it has a drain plug on the convertor. To new for that. Wouldn't hurt to look and drain it if it does.
It wouldn't be worth doing a manual change over, soucing the part would be next to impossable.

 

[B250]

After the holidays I decided to have one last attempt at solving my tranny problem before buying a new one!

I've put this out on the forum in case anyone else is stumped about what is going on with their A500.

This model year had a rod linkage system to the throttle valve on the tranny. The bushings had worn over the past 30+ years, and when I did the WOT check the throttle valve lever on the tranny was not fully to the rear - about 3/8" short.

I also think the rod itself was not OE or had been bent slightly over the years. Anyway, after bending the rod backwards I managed to get the WOT to correspond to a fully open throttle valve lever. Bingo! My A500 now upshifts a few mph faster than the dots on the speedometer, but I can tweak that to get it right.