Anyone had problems where they hear a loud clunk in the drivetrain every 30-100 feet in 4-low?

A quick guess is that I have a jumping gear in the 4-low set...but maybe one of you can point me in a different direction.

FYI: 4-high is fine!

Bill

 

What year truck?

Is this on dry pavement?

Adrianspeeder

 

2002 (BW-1356's were used in F-150's from 1987 on)
not on pavement (I wouldn't use 4-low on pavement)

 

Just incase anyone was wondering.....the problem was a worn shift fork
(low/high) that lost both of its tabs that pull on the lock ring into 4-low.

The cause.....the shop says the electric shift motor was not engaging all
the way, causing it to rub all the time. I hope they are right.....it's
not cheap to take the T-case out just to replace a 40 dollar shift fork.

The worst part of this is that 9 months ago I had the t-case out to replace
a broken case (from rock) and they replaced the other fork (2wd/4wd) because of a similar wear problem. They claim to have missed this one because it was buried in the guts of the t-case.

 

Glad you got it fixed!

Adrianspeeder