Rear Axle replacement

[genolan]

I have a Backdraft #388 (RT2) and the rear axle is leaking. The backdraft web site says there is an old and new type and the new is out of stock. Does anyone know what build the new one was used. Also is there a BMW part number or other manufacture that is a direct replacement?

[spdbrake]

I take it you have a CV boot torn? or is it the the diff?
If you mean the axle/CV:
I would suspect your is a Old style like mine. The inner attach flange at the diff hubs are not as thick (compare the old and new pic on the Backdraft site and you'll see what I mean) and the axles themselves are (most are, not all) fatter in the center section (hollow).

You can't go to the new axles unless you change out the outer hubs (splines are diff)

BMW E30/E36 CV Joint, Boot and Axle Replacement | 3-Series (1983-1999) | Pelican Parts DIY Maitenance Article

Pelican Parts

I'd recommend replacing all the hub bolts and axle nut while your at it.

Also mucho cheaper at NAPA (use a 1993 325is)

https://www.napaonline.com/napa/en/s...tForm-savedveh

[genolan]

I'ts splattering grease so I would think the boot is leaking. I checked and it appears ti match the new axle on the Backdraft website. There is no tapper on each end. Would you know the part number for the newer one or make model year BMW?

[spdbrake]

1996 was the changeover for BMW (Not positive on that) . I'd give Brian @ Backdraftparts a call tomorrow and see the effectivity on the BDR though.

One more thing to inspect, if you pull a wheel and see a bolt in the center hub its the New style, Nut = Old style.

[genolan]

Does anyone know if the spinner has a center cap that can be popped off to identify if the axle is held on by a nut or bolt to identify if it's the new or old axle type?

[spdbrake]

Mine are oringed in. I use a taped up cold chisel and tap - walk them out.

The pin drive nuts use a 12mm allen.

A set like this will work.
[ame]https://www.amazon.com/gp/product/B007UQLQQ4/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1[/ame]

[genolan]

Ok wheel is finally off thanks to 911 spinner tool but I cant get the BDR cap off the axle. I tried a chisel but No good any tricks?

[spdbrake]

Other than taking the hub adapter (See 12mm Allen socket above) completely off you could try a bearing splitter to give you some leverage.
Avail as a loaner from O'Rielly, Autozone, Advance auto.
Bearing Splitter for Cars, Trucks & SUVs

A slide hammer kit with a lockable 3-jaw puller will work but you'll have to buy one like this or Harbor Freight. They are avail for Loan but... you'll have to grind the Jaws a bit to fit the narrow groove you're dealing with.
[ame]https://www.amazon.com/OTC-4579-9-Way-Hammer-Puller/dp/B0015DMNIS/ref=sr_1_2?s=automotive&ie=UTF8&qid=1477763020&sr= 1-2&keywords=seal+puller+kit[/ame]

[genolan]

If I take the five Allen bolts out will the whole assemble come off without removing the brake calibers?

[spdbrake]

Yup that will work. You'll be left with what appears to be a standard hub w/ studs protruding. Rotor hat will still be installed. One - Two studs may come out with Pin drive nut as you remove them. no big deal. Just clean the threads in the hub and stud w/ Carb, Contact, or Brake cleaner and reinstall the stud to the hub using Loctite 272 (Red). Do not put Loctite on the area of threads where the Pin Drive nuts mate.

[genolan]

what torque should I use for the peg drive bolts? Loctite on them? to take them off its ccw correct?

[spdbrake]

Do not put Loctite on the area of threads where the Pin Drive nuts mate.

Standard torque for the BMW 12mmX1.5 lugnuts is 70-80ft lbs. For me 70-80 felt a bit high as internal wrenching lug nuts (tuner lugnuts as some call them) are notorious for stripping in the Allen key area (I have experience on that). I went snug star pattern and approx 30 ftlbs and then 60 ftlbs. There is not concentric locator hub and my concern was more a off-center walk that could cause a vibration.

Replacement pin drive nuts are avail from
Pin Lug nuts Hex head : Vintage Wheels, Mustang, Hot Rod and Muscle Car

Correct on the CCW loosen. If the breaker bar is horizontal, with the breaker bar grip pointing to the left, push down with your left hand.

[mln385]

Originally Posted by genolan

Ok wheel is finally off thanks to 911 spinner tool but I cant get the BDR cap off the axle. I tried a chisel but No good any tricks?

The center cap is sacrificial on this year. Drill hole through center then use slide hammer to pull out.

[genolan]

Originally Posted by spdbrake

Do not put Loctite on the area of threads where the Pin Drive nuts mate.

Standard torque for the BMW 12mmX1.5 lugnuts is 70-80ft lbs. For me 70-80 felt a bit high as internal wrenching lug nuts (tuner lugnuts as some call them) are notorious for stripping in the Allen key area (I have experience on that). I went snug star pattern and approx 30 ftlbs and then 60 ftlbs. There is not concentric locator hub and my concern was more a off-center walk that could cause a vibration.

Replacement pin drive nuts are avail from
Pin Lug nuts Hex head : Vintage Wheels, Mustang, Hot Rod and Muscle Car

Correct on the CCW loosen. If the breaker bar is horizontal, with the breaker bar grip pointing to the left, push down with your left hand.

Thanks for all your help and guidance, I have the wheel and spinner adapter plate off and it's a nut holding the axle so it must be the old style BMW axle.

1) The pin lug were 10mm allen and the hole has anti seize in it along with some debris. Any suggestions on cleaning them? Brake cleaner and compressed air?

2) For new parts I should order from NAPA for a 1993 325is half axle(CV) and wheel bearing correct?

Thanks again as you can tell i'm new to this but I'm willing to give it a shot.

[spdbrake]

Yes on the axle from NAPA.

If your going to leave it apart a few days I'd just toss em in a quart paint can with some lacquer thinner added. Let them soak and give them a shake every day or so. On the hub lug stud holes bores yes the brake cleaner will do it.

The wheel bearing is probably fine (sealed dual roller). Not too bad to change if you want to. (got to love youtube)
[ame]https://www.youtube.com/watch?v=wKYL9_4mXRI[/ame]
https://www.youtube.com/watch?annota...&v=Vedv2OyE9BY

You will need either a E12 or E14 metric torx socket for the inboard axle attach bolts
[ame]https://www.amazon.com/OTC-External-TORX-Socket-Set/dp/B000HT6TUE/ref=pd_lpo_263_tr_t_3/153-2500158-3045527?ie=UTF8&psc=1&refRID=7RR26AF1EZD2ATSP7J03[/ame]

Your feedback on this project is extremely helpful for all of us. I haven't changed a BDR axle yet.

I've just done a lot a research prepping for a future diff swap out.

[6t8stang]

I thought the half shafts from Backdraft were beefier than the OEMs bought from NAPA, etc?

[genolan]

Originally Posted by 6t8stang

I thought the half shafts from Backdraft were beefier than the OEMs bought from NAPA, etc?

The Backdraft web site says original BMW OEM parts so I doubt it's any different and it's 1/4 the cost.

[Cashburn]

Originally Posted by 6t8stang

I thought the half shafts from Backdraft were beefier than the OEMs bought from NAPA, etc?

Only for the later cars (RT3s). Earlier cars have stock shafts unless you buy aftermarket. The new ones from NAPA are best value we have seen for older style cars.

[genolan]

I gave it my best shot but the wheel bearing was stuck on and needed to be cut off. I took it to a local classic car shop and she's ready to go. The parts were a direct fit from Rock auto and NAPA for a 1993 325is. Thanks again for all the help!!

[spdbrake]

Great news and thanks again for the update!