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Ian R11
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VBMWMO #8148
Yorkshire uk
Joined: 10/22/2011
Posts: 206

I have looked at some earlier forum topics regarding clutch friction plate thickness. I didn't see a defined unworn thickness.
Does anyone know the "as new" thickness of the friction plate? Mine is 5.7mm, bonded and having no rivet holes as clue to condition.

Gearbox now back together, and oil ways clean and functioning well in engine. Cleaned with ultrasonics! I have been recommended a castrol SHL 00 liquid grease for the gearbox. Does anyone know how well this works in colder climates?

Darryl.Richman
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VBMWMO #6285
Surf City, USA (Santa Cruz, CA)
Joined: 10/27/2006
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I don't recall for certain

I don't recall for certain what the clutch thickness was for my R52, but I think it was 7mm. I think it also varies depending on whether you have a single plate or dual plate clutch setup. From your post, it sounds as though you, like me, have the single plate arrangement.

"Liquid grease" doesn't sound right to me (I'm not familiar with the product you mention). The R42 gearbox was designed to be filled with grease, but the R52/57/62/63 came with BMW's first transmission intended to be filled with motor oil.

A Google search found this: http://www.castrol.com/castrol/sectiongenericarticle.do?categoryId=82915...

Castrol wrote:

Castrol SHL 00 is a synthetic, semi–fluid NLGI 00 grease that combines the stay–put power of a grease with the consistency of a gear lubricant. As a result, Castrol SHL 00 virtually eliminates fluid leakage from wheel seals, hubs and axles, which can be a serious environmental and safety hazard for over–the–road fleets and can increase maintenance costs. Castrol SHL 00's synthetic base stock gives it excellent low temperature mobility and high temperature stability. NLGI 00 lubricants are recommended by The Maintenance Council in their Recommended Procedures for Wheel End Lubrication (RP 631). Castrol SHL 00 can also be used in quarry, industrial, mining and construction applications where a semi–fluid grease is recommended.

This quote, along with other text at the Castrol website, indicates that this product is intended for wheel bearings in long haul trucks and heavy construction vehicles. It says nothing about its applicability to high pressure situations such as are seen in transmissions.

Perhaps it was recommended to you because of its ability to stay put behind less than perfect seals, such as the felt seals used in this transmission. It is true that regular oils will weep past the felt seals, although my experience has been that this is a minor annoyance. (Curiously, the modern lipped seal on the nose of my R52's final drive weeps much more oil than any of the felt seals on my bike, and makes much more of a mess, too.)

I have been running my R52 with gear lube instead. I believe that any gear lube will far outperform BMW's original motor oil specification in this situation. If you are concerned by the talk about Hypoid oils (GL-5) attacking "yellow metal" (eg, brass or bronze bushings), then look for GL-4 spec lube. I personally have never had a problem with GL-5 and I've been running GL-5 in my /2 transmission for 16 years and my /3 transmission for 7 years.

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Bruce Frey
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VBMWMO #6316
Texas Hill Country, USA
Joined: 10/27/2006
Posts: 574
I don't know about the R62,

I don't know about the R62, but the 2 clutch plates for an R12 should be 6.0mm (this is from Huggett). Almost all of the reproduction clutch lates are considerably thicker, which may present problems with disengagement. For the R12, Vech at Bencmark works suggests using hardened steel washers as spacers to deal with thicker clutch plates.

The "grease" for early transmissions was, I believe, like a heavy oil. If you are familiar with outboard motors, the lube for lower units was also called grease. The Castrol product sounds like a good choice to me. In addition to the gear lube Darryl mentions, I think that outboard lower unit lube should also work.

Bruce

Ian R11
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VBMWMO #8148
Yorkshire uk
Joined: 10/22/2011
Posts: 206
Thanks for replies. I have

Thanks for replies.

I have asked Dreher for thickness of new friction plate and I am informed 7mm. He thinks mine is still serviceable at 5.7. I am still tempted to reline, it's not the easiest clutch to swap later.
A good point will be to check the disengagement.

I am probably answering my own question regarding gearbox, it has oil pickup built into the casting and drillings to scavenge the bearings. I don't think these would work with a very thick lubricant. The thick oil in the box before strip down also created a large amount of drag on the free spinning gears. I can't imagine this would help gear change. My R11 seems good on sae 90, and I think all the teeth are still in there!

Darryl.Richman
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VBMWMO #6285
Surf City, USA (Santa Cruz, CA)
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Ian, is there any chance you

Ian, is there any chance you could post a photo of your 2nd gears? As I am going to be participating in an almost 4,000 mile ride on my R52 next fall, I am concerned about the longevity of that 2nd gear, since you have to push it into and out of mesh each time you pass through 2nd gear.

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Ian R11
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VBMWMO #8148
Yorkshire uk
Joined: 10/22/2011
Posts: 206
Hi Daryll I hope the photo's

Hi Daryll

I hope the photo's download and show ok. I am no computer wizard and it's taken me longer to compress these than put gearbox back together!

If you need any better or more specific in detail let me know, and if I cant do it my son can!

Sounds like a great trip and look forward to a report on it.

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