Oil change & gear lube underfilled?

[gram10]

I'm at 6,000 miles, this weekend I did the front diff, transfer case, and rear diff fluid. I followed the first post in the trx forum thread I posted above.

Front diff - semi dark, definitely some metal, nothing crazy though
Transfer case - pretty clean
Rear diff - dark also with metal

 

[Steadi]

I'm at 6,000 miles, this weekend I did the front diff, transfer case, and rear diff fluid. I followed the first post in the trx forum thread I posted above.

Front diff - semi dark, definitely some metal, nothing crazy though
Transfer case - pretty clean
Rear diff - dark also with metal

We’re any of these low from the factory on your truck?

It seems like you have more miles than most on this forum. Any problems to report?

 

[gram10]

We’re any of these low from the factory on your truck?

It seems like you have more miles than most on this forum. Any problems to report?

No problems, just figured it would be a good service to do early on. I'm not sure if any were underfilledl, i didnt bother checking as i was refilling anyway. I can say that none of them leaked any fluid out of the fill plug hole.

 

[ah64aviator]

Just completed my 1st oil change on RHO at 1206 miles…why?

This engine is very similar in output & configuration to the current BMW M3/4 Competition. BMW recommends that engine & all differential fluids be changed at 1200 miles. They are so serious about it, BMW even pays for this $2400 service.

Our differentials are not limited slip, so I’m just going to follow the “severe duty” recommendation of checking/changing the fluid at 30K miles, though I will probably confirm the front diff is full at some point in the near future (many came 1/2 quart low in TRX).

Transfer case is another story. Since there are clutches & slip (heat), that one is getting fluid changed out at 2500 miles.

For the oil filter removal, I used a 74/76mm 15 flute cap. The drain bolt is 13mm. I drained approximately 7 3/8 quarts total from the engine & filter. Guessing the additional 1/8 quart is in the filter media. The MOPAR filter part# is 68566307AB, and I got .4 quarts into it before install. Oil is factory spec Penzoil for SRT 0W-40.

Easy peasy. No need to remove any skid plates or jack it up. Though, a 6” socket wrench extension is highly recommended (by me).

I don’t have any torque specs for the drain plug or filter…did them by feel, as I’ve done for many vehicles over the years. The oil filter does have a pictorial on the side that appears to indicate it should be hand tightened + one turn. Maybe my hands are too strong (ha!), but 1/4 turn with the wrench after hand tight felt PLENTY snug!

Good info. Thanks for sharing! Curious, what is the prescribed the transfer case fluid change?

 

[Fast1al]

Just FYI…

The ZF unit has a filter & several strong magnets in the disposable pan. Ram says its lifetime fluid & fleet techs have reported few fluid relayed failures, even over 150K miles.

That being said, ZF recommends fluid changes between 60K-80K miles, depending on usage. It’s a sorta complex procedure that typically requires a lift & warming/shifting the transmission to prime the unit correctly.

Just an FYI my 2014 Ram had a ZF transmission. I got rid of the truck at ~140k miles because the transmission starting acting up, it would cause the whole truck to shake and shudder on occasion. The dealership drained the fluid and inspected it, told me some valve seals were leaking and I’d need a new transmission. They replaced the fluid and I planned to get rid of it. However after the fluid change it drove so much better and I didn’t experience that shudder again. My 2024 Land Rover Defender also had a ZF 8 spd. They recommend a 60k fluid change and that’s what I’ll be doing on the RHO. The ZF transmissions need their fluid changed! The service is ~$1,000 at dealership.

 

[Fast1al]

Can anyone confirm the oil filter wrench flute size? Just did my 1k mile oil change and I tried using a 15 flute and it felt loose / kept slipping. Thankfully I was able to use a rubber strap wrench and get it off. I freaked out for about 10 minutes that thing was sooo tight! I used a cheap auto parts flute wrench, wondering if that’s the issue. Maybe it was the size or do I need a deeper, better quality one?

 

[RHOfan]

Can anyone confirm the oil filter wrench flute size? Just did my 1k mile oil change and I tried using a 15 flute and it felt loose / kept slipping. Thankfully I was able to use a rubber strap wrench and get it off. I freaked out for about 10 minutes that thing was sooo tight! I used a cheap auto parts flute wrench, wondering if that’s the issue. Maybe it was the size or do I need a deeper, better quality one?

I used the 74/76mm cheap auto parts store filter cap/wrench. You do need to be sure it’s full seated (not being blocked by the head of your ratchet extension), or it can slip.

I assumed it must be 74mm since a 74/76mm cap is 74mm when fully seated, but a 74mm wrench didn’t fit. Odd, but that was my experience.

 

[gram10]

I've had good luck with one of these kn my past few cars with conventional filters, works well for the rho too

2-1/2" x 3-1/8" Oil Filter Wrench - Lisle 63600

2-1/2" x 3-1/8" Oil Filter Wrench - Lisle 63600

www.fcpeuro.com