Stripped Final Drive Fill Hole

[Bob_Roller]

Got enthused with the project LS the past few days, took it around the neighborhood to warm up the oils and drain them .

When I removed the fill plug for the shaft, found the threads stripped .

Anyone taken the final drive apart ?

From the looks of the manual, you need some specialized tooling, just wondering if you can get by, or just have a shop do the work .

The BMW shop I contacted had a quote of about an hours worth of labor, cost of new seals and then around $50 to have the housing sent out for a threaded insert to be installed .

[montmil]

Bob, With your experience, you ought to be able to fab up a fix yourownself, I'm gonna quit flying Southwest if you can't! I'd study the issue for awhile before investing a couple C-notes at the stealership.  Just my  [smiley=2cents.gif]

Monte

[Bob_Roller]

This shop, is an independent BMW repair shop, labor rate around $80/ hr .

After I get it removed, I'll make my decision on which way to go .

[benita]

yeah,I had the same thing happen to me a few years back.what I used is a Heli-Coil kit. When I drilled the oversized hole before tapping the hole I made sure I smeared alot of grease on the tip of the drill bit,as to catch as much drilling debis as possible.Go Slow,its only aluminum!The Helicoil kit you need is : 5546-8.The tapped hole size is M8X1.25.And the actual drill bit size you need is 21/64.It won't be the exact pitch on the thread as the original.If you want the same tread pitch size the helicoil kit is available, but is more than double the price of the kit 5546-8.For the 5546-8 kit cost me a few years back $30.00.The 5546-8 kit thread pitch is a little coarser then the original.You will have to use a M8X1.25  short bolt instead of the original bolt.Beleave me ,it will be better than new when finished

[Landlubber]

...if you do decide to drill and tap, then do it upside down so that it helps even more to keep crap out of the hole.....

[bruce_launceston]

The final drive fill hole (the one for the drive shaft, not the rear bevel drive) is M12x1.5.
The bevel drive fill hole looks to be an M18x1.5.

You could get a helicoil or a recoil kit for M12 but it is a very 'short' hole so I don't know how well it would work.

[Bob_Roller]

I think I'll just remove the final drive from the bike, remove the 'innards' and take it in .

For $100-130, it will be done correctly, without the possibility of having pieces of metal get into the bearings,  then turn into a costlier repair in thr future .

Guess it's the cost of having 30ish year old motorcycles .

[steven m]

Have you considered just gently re-tapping the hole by hand and then putting in a threaded sleeve?  If you are very careful and take your time you should be able to keep the cuttings out of the drive.  Note the emphasis on should.  Yeah, the fill hole would be smaller, and would require a new bolt, but if you are going to strip it down anyway why not give it the five dollar try first?

Just my two cents...

Steve

[Bob_Roller]

The problem, is removing the input shaft, you need a couple of specialty tools to accomplish this .

Without the shaft and bearings out of the way, there is almost no clearance between the shaft and final drive housing, not a lot of area to work in .

I just don't want to get metal into the bearings and cause more problems later on .

I've tried a few times to get situations like this repaired myself, they didn't come out very good .

[steven m]

Yes, very tight in there.  By the time it is all apart and repaired, including your time, transit time, etc., it may be less expensive to find a used unit in good shape and just bolt it in...

I still think you could find a stainless steel sleeve and gently, repeat gently, screw it in.  A tiny shaving in the drive shaft compartment, I know, this is heresy, and not the final drive, shouldn't be the end of the world.  But then again, if it was my bike I'd want it done properly too.

It's a conundrum...

Steve

[Bob_Roller]

The shop is local, only a 10 minute drive away, removing the final drive is about a 45 minute job .

About another 30 minutes too remove the 'innards' of the final drive, so all the shop has to do, is to remove the input shaft, install the thread repair, reinstall the input shaft, about .75 hours of labor .

So it looks like around $100 total cost .

My only problem with another final drive, is that you may get one that's in worse condition than what you already have .

[Bob_Roller]

Got the final drive back yesterday, total cost was $130US, a few other minor problems were found with the final drive, so the cost was about $30 more .

Brought everything into work today, slow day, so I'll have it all back together by the time I go home .

79 F in my shop at work, 94 F in the garage when I left for work at 0515 this morning, I don't look forward to working in this heat, it's been around 110-112 F. every day this past week, too bad I can't bring my bike into my shop at work !!