1997 4cyl auto trans problems.

steepletown · #1 07-14-2010, 09:20 AM

My 1997 XLT 4cyl standard cab has 50K miles. When cold it shifts into both reverse and drive with a vicious 'clunk'. Sometimes drive is slow to pick up. The selector is in D but the truck does not want to move. And sometimes moving from Drive to Neutral engages reverse (sort of!) Fluid and electrical connections checked. Appreciate any good information. Thanks.

sgtsandman · #2 07-14-2010, 10:19 AM

How old is the fluid? It should be changed every 30k.

rangerhippie · #3 07-14-2010, 10:50 AM

Sounds to me like the vacuum modulator. The A4LD is a vacuum shifted trans and the modulators have a reputation for failing. an easy way to check and see if its bad is to pull the vacuum line for it and see if there is trans fluid in the modulator. It is located on the passenger side of the trans just in front of the tail housing and just above the pan on the case. If you pull the vacuum line off it and fluid comes leaking or squirting out you know that the modulator is bad.

If you haven't done a ton of driving you may just be fine replacing the modulator. If not though because of the failure you may have torn up your clutches. In that case the trans would need to be torn down and clutches replaced. The good news is that if that is the problem rarely is anything else wrong besides bad clutches and modulator.

One last thing to add. If it comes down to being the modulator i'd recommend replacing it with a heavier duty adjustable one. they last much longer and are much more reliable. The stock units are really hit or miss.