Retorque Drive Shaft Flange Bolts

[KevinK]

Hi,

Lexus recommends to retorque drive shaft flange bolts every 15k or so. Can someone please describe the procedure? I am sure many others will appreciate this also.

Thanks very much.

[KevinK]

Anybody? Please!

[wwest]

I have assumed that is a dealer "make work" routine. I have heard it only applies to the rear driveline of AWD models. My 01 AWD RX300 has about 35k miles and I'm not at all concerned about retorqueing drive bolts, or whatever.

[KevinK]

Thank you. But, this service is listed in the maintainence schedule. I am concerned that not doing this job may cause problem or void warranty.

[BVoyles]

I agree KevenK, it says to re-torque the flange bolts in my maintenance manual at 15,000 miles also. I just won a full 2 book maintenance/repair manual on ebay. Once I receive the manual, I'll let you know what to torque the bolts to and where they are located.

[wwest]

I have the shop manuals and insofar as I can determine they have no specific indication of which drive bolts the owner's manual refers to. If I actually wanted to know I would go and ask the Lexus service manager, they are usually quite friendly (even to me, wow!) and willing to help.

But be prepared for a sales pitch about some add-on or another.

[BadBrad]

I've been planning to climb under the ride and do this myself. Although I've not been under there yet to peek I will say that most driveshaft bolts are quite exposed and usually easy to find. If this is the case all you'll need is a torque wrench which you can pick up from Harbor Freight tools for $20 or less (micrometer type) on the web. All we really need to know is how many pound/feet or newton/meters we need pull on these bolts. When I do it (by the way) I'll probably crack 'em loose, deposit a drop of motor oil, and then pull them tight.

So - how tight do these need to be? I'd bet 45 lbs/ft.

[wwest]

A drop of motor oil...? NO! NOT!

Anti-sieze compound maybe, but NEVER motor oil. Torque specifications are predicated on non-slippery threads.

[BadBrad]

Apparently you've never built an engine yourself before, otherwise you'd have known that oil on the threads and bolt heads is common practice if not a requirement. The friction between a dry bolt head and dry mating surface does nothing but bind the bolt early which in turn may yield a false reading on the wrench. Torque specs are different for dry and wet bolts. A dry bolt with a spec of 12 lb/ft runs only 9lb/ft if wet. So your "NO! NOT!" is just NOT! appropriate - there are times when wet bolts are right.

Back to the original question - we're all still wondering what the spec on these bolts is.

[riwyle]

I must support Mr. West on this one. Unless specifically stated otherwise, recommended torque values, which are derived by test to give required bolt stretch, are always for clean, unlubricated, ambient temperature bolts. Although "shade tree" mechanics that believe otherwise can get away with over-torque in most situations, I always believe in following engineering/ manufacturing standards as quoted above.

[toyo]

The 4 bolts that attach the rear propeller shaft to the rear diff housing is 54 ft.lbf.

[sveet]

Can somebody direct me to a decent quality torque wrench?

I have one but I don't realy trust it.

[BadBrad]

Harbor Freight Tools sells a Pittsburg 150# micrometer style clicking wrench for under $20. Comes with a case. I use mine all the time and build engines (that don't break) with it. If you're ever concerned about calibration, engine machine shops in your town can probably check it out for you.

The key for these is maintanence. Never store the wrench without loosening the spring - twist the micrometer handle back down to around zero pounds.