how to repair Mahindra 3525 leak at bull pinion brake shaft??

2manyrocks · May 1, 2023

I suddenly noticed my brakes weren't working like they should. Pulled off the drum on one side and found glazing on the fiber brake disc. Installed new one after cleaning the brake surfaces. No big deal there.

But when I removed the drum on the side where the differential lock engages, I noticed what appears to be gear oil trapped between the brake mounting flange and the transmission gear housing. The red arrow shows the top of the flange, but the oil was trapped at the bottom of the flange below the bull pinion shaft.

Mahindra's on line parts showed the brake shaft seal (0000000RS) as no longer available, but finally got to a dealer parts guy who gave me a new part number for the substitute seals. There are two of them that are $35 each. Part no. 006500038R92.

Dealer estimate to replace the seals is $2,000 at $110/hr labor rate plus $275 pickup one way 60 miles to the dealership. They said they may be a little high on the estimate, but will only charge the actual time involved. They said they don't have to split the tractor, but that it would take about 12 hours if I remember right. They didn't seem to want go into detail as to what has to be done when I asked what they had to do to make the repair. I think the guy talking with me wasn't personally familiar with the repair and was depending on his shop supervisor to tell him how it had to be done.

The rear tires are filled with ballast and weigh about 460 lbs.

This Mahindra 3525 is about 20 years old with 767 hours on it. I'm not too happy at the prospect of spending $2,500 to replace two seals when I paid $11,000 for the entire tractor with loader in 2014. These two seals apparently are on this one brake shaft. There are seals on the other brake shaft on the other side. I'm wondering if the seals on the other shaft also need to be replaced while they've got the tractor torn down?

Does anyone know what is really involved to replace these seals? Do they have to remove the hydraulic assembly from the top of the transmission case to access and repair the seals? Does the Mahindra Service manual that costs about $100 cover this in enough detail that I could make this repair or do I just suck it up and pay the dealer?

2manyrocks · May 1, 2023

Update: there are a few instructional videos on these Mahindra brake seals on youtube without English translation. However, it looks like the brake assembly on my Mahindra 3525 is very similar to "late model" International Harvester tractors like the B414, etc. There is a detailed explantion of what is required to replace the brake seals on the IH tractors here: International Harvester Bradford Built Tractor Brakes

The key points I am reading are that the hydraulic assembly and drive axle have to be removed in order to remove the bull pinion gear to get access to the differential housing to replace the brake seal. The seals on both axles should be replaced at the same time because of all the work required to replace the seals on one side.

So basically, an IH mechanic who worked in the 1970s should be able to do this job if what I read is correct and if I am understanding it right.

5030 · May 1, 2023

Just my personal opinion but I think I'd put it back together and put it on Tractor House and sell it and buy a tractor with wet multi plate brakes, your choice of brand. I do know my Kubota's have wet, multi plate brakes and I've never adjusted them or had any issues with them in thousands of farming hours. Sounds to me like a very involved job.

2manyrocks · May 1, 2023

I'm still mentally processing the severity of this issue.

I am reading that there is a weep hole that is supposed to be open. I was able to wipe up the oil that was present with a couple of Q tips. I don't know if this assembly is designed so that some oil that passes through the weep hole is tolerable or if the presence of any oil means the seals must be replaced?

It looks to me as if Mahindra just continued with the IH design right down to the problem that a lot of disassembly is required just to replace two seals instead of updating the design to allow for easy replacement of the seals, externally.

I was friends with the best International mechanic around for years before he passed. He would have known everything there is to know about this job.

Harry in Ky · May 1, 2023

For what it's worth, just skimming the 3525 parts lists, it looks to me the seal in question fits into the support for the differential carrier. From the inside. My take is the support has to come off to get to the seal. The bull gear and pinion combo they used looks like the axle housing and bull gear need to come off before it will come out. Hydraulic lift housing would need to be removed to support the ring gear and carrier while the support is off.

Yes, I'd say it's a majorly labor intensive project. No fun to do yourself, nor cheap to hire out.

2manyrocks · May 1, 2023

Another consideration is I don't have a shop space suited to this project.

2manyrocks · May 5, 2023

I dropped by the closest tractor dealer who sells another brand and asked the service department if they would work on my Mahindra. "No. It's a nightmare getting parts."

2manyrocks · Aug 16, 2023

To wrap this up, I've been calling the Mahindra dealer who sold me this tractor for months to ask for an estimate of repair cost. Every time, the service guy is not available to talk and doesn't return my calls even after I spoke directly with the owner about needing help and asking the guy to call me.

So I contacted another Mahindra dealer and got the service estimate I mentioned in my first post, but there is a pretty substantial mountain to climb to get to the second dealer from my place. And I really don't know anything about their service department never having dealt with them.

I called the dealer that sold it to me again this week. The service guy is still not available to talk on the phone. Then I get put on hold twice...and then they tell me to call back. I still haven't gotten any estimate from this dealer.

So my conclusion is that there's no point keeping this tractor with this kind of continual lack of customer service. I traded it for a Kubota MX5200 to another independent dealer who will repair it themselves, and it left my driveway today.

5030 · Aug 16, 2023

One issue I don't have and gladly I don't. The head tech at the Kubota dealer I deal with, I have his private cell number and we talk all the time anyway. I shoot at the same club he does. Heck, I know his wife and kids too. Same with the parts manager, he lives about 3 miles from me and farms like I do and I've said before, if I need anything like filters, he drops them off here at the farm, don't even have to go to the store. Even know the owner personally, that happens when you deal with the same dealer for 25+ years.