# Differential Lock seized MF 135



## pletzvet (Feb 11, 2013)

I recently acquired a 1969 Massey Ferguson 135 diesel. I'm doing a full restoration (no engine rebuild). I discovered that the differential lock is seized up tight. I'd like to hear from anyone who has had success in getting this thing loosened up and working without having to remove the trumpet housing. I've applied PB Blaster, Rust Check, and creeping grease for the past few weeks - no success. This week-end I resorted to using heat. I applied most heat on the outside bushing (which I suspect is the culprit) and some heat to the housing bushing but didn't want to risk damaging the seal. Anyone have any luck loosing this thing up?:argh:


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## sixbales (May 18, 2011)

Howdy pletzvet,

Welcome aboard the tractor forum. 

Apparently this is a relatively common problem with 135's, and other MF models as well. The pedal may be stuck down due to a rusted shaft, and/or the diff lock mechanism may be broken internally. Does the tractor steer/turn freely, or does it tend to go straight when trying to turn? If it steers/turns freely, then the diff lock is not engaged, even though the pedal is stuck down in the engaged position.


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## pletzvet (Feb 11, 2013)

Thanks for your reply sixbales - sorry, I didn't clarify...the lever is not stuck in the engaged position. The rear wheels are free-wheeling. I'm thinking (and hoping) that its just seized due to rust around the bushings from being left out in the weather. I've heard that one of the best penetrating fluids, is a homemade blend of automatic transmission fluid and acetone mixed at a 1:1 ratio. I'm going to try that - I've got time and patience on my side. ha ha. Hoping that it will eventually free up.


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