Meritor ZF Freedomline - Repair or replace

Please only comment if you have experience, your opinion on auto shift transmissions or freedomline v eaton v I shift is not want I am asking. I have a problem with my transmission and it will be fixed. Throwing it in the rubbish bin is not an option.

with that said, here is my situation....i have 12 speed freedomline in my 780 volvo with the D12 engine. The freedomline is working just fine and I am happy with it's performance. However, I am lately experiencing a noise and vibration when in 12th and cruising off power, being pushed by the weight in the trailer. As soon as the engine powers on and puts power through the transmission the issue goes away. I know it's in the freedomline because if I shift to neutral when the noise/vibration is there it goes way. Rev the engine cruising in neutral I get no issues, so it's not the engine. A freedomeline specialists in Dallas TX thinks I have play in the bushings that carry the 12th gear and as a result I am getting gear slop off power which is causing the noise and vibration.

so my question is simply..repair or replace. A rebuilt unit is approximately $10k installed with a one year warranty. I currently have 694k on the truck, so I am concerned that if I go for a repair now which will be cheaper upfront any later issues that need to be fixed will cancel out the repair v replace savings. This is a mechanical problem, all the electrical and air related systems on the box are working just fine.

thanks in advance for informed replies.

 

Interesting...what you wrote v6killer made me think, I have noticed when I go over a bump in the road the pitch of the noise changes. Also the issue is not evident as soon as power is lifted off in 12th. It does come and go, and is more intense the heavier the load in the trailer. The issue almost goes away when I run empty.

thanks for the reply.

 

Please...just FYI Volvo does not make the transmission, driveshafts or the axles. So the problem has nothing to do with a Volvo manufactured part.

 

Thanks for the input Boardhauler, you have echoed my thoughts. Go cheap to start and work up the list to most expensive. As far as I know, the UJs are all original and are the sealed non grease able kind. So I would have replaced these anyway if I went for the new tranny. So doing them before the tranny is no big deal.

Plan of action as follows:

check ride height - easy to do right here right now and easy to adjust if out.
level valve - get new one

problem not solved then..

rebuild driveline - new UJs and slip yoke

Then lastly if problem not solved...

install rebuilt tranny.

 

Update...

Measured ride height and by my calculations it was about 1.5 inches to low. Passing through Yakima WA this morning, so popped in to the Volvo dealer there. They confirmed the low ride height. Pulled the leveling valve and it was shot. New valve in and all is good. Rides like a Volvo again. Another excellent experience with the guys at the Yakima dealership.

v6killer & Boardhauler thanks for the help.

 

Ride height was the problem not the gearbox. Apparently the ZF box is extremely robust and mechanical issues apart from clutch wear are almost none existing. Electrical gremlins are the ZFs downfall plus the cost of parts in general.