TLAV transmission won't upshift from 1st

[Malcolm Towrie]

Good info , Paul. Thanks. It would be easier to find the diagnostic port and borrow a scanner to monitor the speed sensor and look for codes, but if that doesn't pan out, we'll need to track down the speed sensor and I have an automotive oscilloscope we can use to check it out.

We'll check if the speedo has quit also.

One of the mechanics working here just told me his shop has a scanner for road-going Allison trannies. The TLAV has a specific military model of transmission but if it has the round 9-pin diagnostic port, we may be able to at least read the codes.

Malcolm