Case Dozer transmission seal problem

[justin1085]

I am going to look at a Case 550 dozer that is for sale. The owner has been having problems with the transmission seal blowing. He stated this is the seal between the engine and transmission and requires the transmission to be separated from the engine to change. He stated that he has now changed the seal twice and each time has got less than one day of work out of the machine before it blew again.

Question is what would make the seal continuously blow? I'm sure there is a breather on the transmission that could be plugged?

I'm not sure of the details on how many hours or what year the machine is. I believe this is going to be an 80's model. The owner has had it for the last 10 to 15 years. Has a new final drive and 80% undercarriage. The owner is willing to sell this cheap (5K) because he is tired of working on this problem. Just trying to get an idea of what I'm walking into.

Any ideas or thoughts on this would be appreciated.

 

[Bob Rooks]

Are you talking transmission or torque converter seals?

 

[justin1085]

Not sure, he said the transmission seal? he said it was a $20 part but a lot of work to change it because you had to split the transmission from the motor. I will be going to look at this this weekend and hope to get a better info on it.

 

[Bob Rooks]

My guess is the torque converter seals, they are the most common to go, but not that often. Could be an alignment issue from worn shafts, etc.

 

[EddieWalker]

No idea on the seal, but I have found it to be very common for somebody trying to sell a piece of equipment to lie about what is wrong with it by saying it's something simple, but he's just tired of messing with it. If it was simple, he could pay a mechanic to do it in a day or two for a grand or two, and sell it for a lot more money. If you don't know what you are doing or have any experience with that type of machine, then it's worth the money to buy one that it in running condition and not have to fix it before you can use it. $5,000 is too cheap for it if that's all that's wrong with it, and it sends up red flags for me to run away from it.

Eddie

 

[justin1085]

I actully think the problem he is having is legitimate. I know the family and work with his son who had told me about this problem in the past, before I was interested in buying a dozer. I honestlly dont think they know whats wrong with it... I suspect it needs some work to correct the problem that is making the seal leak. I am mechaniclly inclined but dont have a lot of experance with dozers....i took a couple of years of agricultural mechanics in school but thats not too much experience. Well I am going to look at it in person and see what can a shape that is in, if it looks OK to me I will hire the local CASE dealer to do an inspection for me before buying. That may save me a world of headaches in the long run!!

 

[Bob Rooks]

Torque converter seals are more than $20.00. I suppose it's possible that he's been replacing the wrong seal all this time. Stranger things have happened :shocked:

 

[TraderMark]

Justin,

A little more info please?
There's a serial # break in the 550 dozers at JAK0013968.

I'm going to assume that he's talking about torque convertor seals also, since the actual transmission seal would require only the removal of the driveshaft between it and the torque convertor for replacement. Also, the torque convertor housing is what bolts to the engine, not the transmission housing.

The torque convertor drives the transmission charge pump, very much like the automatic transmissions in cars. There could be wear on the stub of the convertor that's damaging the seals. There could also be wear in the bushing inside the charge pump that's allowing the stub of the convertor to move enough to damage the seal.

For the later models, after the serial # break the convertor seal is a $21 part. Before the serial # break it's a $40 seal, but both require removal of the convertor housing from the engine.

Take a look at the attached diagram for the later models. Items 20,21 and 22 are the seal and bushings.

Hope this helps!


Mark

 

[cartwright]

i have case 550e dozer with simaler problem tork converter seal leaks have figured out to much presure but dont know why