differential oil

[Hotrod6169]

Hey I got a 04 Monarch 2, any special differential oil I need to be using on a trike? I heard that the synthetic is not good to use?

[Lee H. Mann]

Lehman recommended 75-90 gear oil (non-synthetic).

I have used only synthetic for the last 18 years on all shaft-driven builds (200 or so) without problems provided there are no leaks.

[Hotrod6169]

Lehman recommended 75-90 gear oil (non-synthetic).

I have used only synthetic for the last 18 years on all shaft-driven builds (200 or so) without problems provided there are no leaks.

cool, thanks Jim

[Mick]

Jim mine has a leak what do you do for leaks from the seal at the front of the differential?

[Lee H. Mann]

Jim mine has a leak what do you do for leaks from the seal at the front of the differential?

Pinion Seal time ...... clean the front of the differential housing with Brake-Kleen and determine exactly where the leak is.

Seals leak from 3 different places the inner rubber surface, the outer housing to seal surface or the pinion splines themselves.

The last two can be corrected without changing the seal.

Since you have a Monarch II, if you haven't change the 3 bolts on the differential cover and are planning on a pinion seal, now would be the time.

[Mick]

Unfortunately with mine I no longer have the ability to do major work like that and the closest dealer to do it is 242 miles away and I would have to stay at a hotel overnight while they work on the trike. Im running Redline 75/90 hypoid oil in the rear right now.

[Lee H. Mann]

Unfortunately with mine I no longer have the ability to do major work like that and the closest dealer to do it is 242 miles away and I would have to stay at a hotel overnight while they work on the trike. Im running Redline 75/90 hypoid oil in the rear right now.

Mick, Don't let it run low.................

Here are 2 examples of running them out of oil.

Frankly, I have never seen a pinion shaft bend at the gear or run all of the teeth off the crown and pinion.

Very expensive repair and new gear sets are becoming unavailable.

[CrystalPistol]

Even sawdust and oatmeal would be better than letting run dry.

Mick, if you have a local mechanic whom you trust to do like work on your 4 wheelers, talk it over with him. Even if you need to buy some ramps, worth it I think.

We have a '08 Mustang with Ford 8.8 rear that was leaking at the pinion seal, I removed the vent cap which has a very lightly spring valve or flap, and I installed a fitting with hose routed up to the frame. No more leak.

[Mick]

One thing Ive noticed is that it seemed to leak more with synthetic than standard gear lube. I wound up putting an ounce of ATP reseal to stop it. I called a dealer one time to fix it even spent a night at a neighboring hotel so I could have it fixed,the dealer tells me the lehman shock is shot changes it doesnt want to hear what I say and I get home and iiiits still leaking. I dont even have a local shop to take it to because the place that repaired my cars for the past 20 years the father passed away and the kids sold it.I just dont feel like fighting the dealer again as its a 240 mile drive down to them. Al was retired already when it started to leak and Jim I wish you were closer.

[Mick]

I checked the vent tube and its open so the differentials breathing okay. I have ramps but no room and noone to help me with her and sadly being by myself theres noway Im going to attempt to do this.