TN65 Rear Differential Leaking

[rawaits]

I have a 2004 TN65 4wd with 330 hours that sits a lot and recently, after sitting about 4 weeks, I noticed a puddle of gear oil under the rear diff. Upon examination, it seems to be coming from the lower right pin that the right-lower 3 point hitch arm mounts to. It doesnt seem like it should be designed so it can leak there as the arm merely pivots on the pin and why would the diff fluid be bathing the back side of that? It is a puzzle and an even greater puzzle how to fix it, which I would like to do myself. Does anyone know what is indicated by a leak here and what would be involved in repairing it. THe puddle was about a foot in diameter and the fluid level was at the add mark. Many thanks. Rick

 

[TractorTech]

The shaft is the draft torsion shaft and the leak is from a seal. You have to drain the rear axle, take off the 3pt. linkage on that side and remove the 2 bolts holding the seal housing in place. Sometimes the housing with the seal and bearing slides off easily and sometimes needs to be heated as the bearing tends to rust to the shaft. Once off, there is a seal that you pry out and replace. Assemble everything back and fill with oil.

 

[RickB]

There is another thread on this topic with very good info.

 

[rawaits]

Thanks very much for this info. I will tackle it myself.

 

[Springtx]

I have a similar puddle u deer my rear diff on my TN65. I was wondering how your repair worked out and if you have any advice before I get started on it. I wasn't able to find the other thread on this topic.
Thanks

 

[picanoor]

I also have a leak on my tn 65 but mine is at the wheel so it must be the outer seal, is assume, do you have the take half the axle of to pull out the shaft and seal, or is there a locking ring on the out side as well? So you only pull out the shaft!

 

[Parksman]

I just replaced the seals on both lift arms on my TN75D. I was very nervous about the process but it's a very easy fix. I used the opportunity to change the hydraulic filter and all of the hydraulic fluids at the same time. The assembly diagram I got from the dealer did not show any type of snap ring or lock ring holding the seals in place. However, after I removed the housings that hold the seals, there was a lock ring in the housing. It's not a typical snap ring that is easily removed. It's more like a heavy gauge wire that snaps into the groove that's machined into the housing.

I took both housings to the NH dealer and they pressed them out and pressed in the seals I had already purchased from their parts Dept. it took about 20 minutes and cost $37. It was money well spent and I had it reassembled in 30-45 minutes.