Rear Diff Bolt Substitute

[eacmen]

For me the rear diff e-torx bolts were hard to get off with the trunk getting in the way of getting a real socket on it. I had to use a swivel and 3/8 breaker bar. The e-torx bolt heads also came out sort of mangled. Curious if anyone has considered replacing it with a normal bolt head so that there are more options for low profile sockets?

Was considering replacing the bolt with this:
Class 8.8 Steel Flanged Hex Head Screw, Medium-Strength, Zinc Plated, M12 x 1.75 mm Thread, 50 mm Long | McMaster-Carr

Same thread and grade. Also flanged like the original bolt.

Thoughts?

[bigjae46]

That would work as long as same grade. I prefer the e-torx heads because if the head gets screwed up you have a second chance to get it off with an E-torx socket a size larger.

[eacmen]

That would work as long as same grade. I prefer the e-torx heads because if the head gets screwed up you have a second chance to get it off with an E-torx socket a size larger.

Don’t you mean a socket size smaller? And at that point wouldn’t you need to hammer the socket on? So you’re dropping the subframe already?

technically e-torx can handle more torque than a regular hex head. But the cost is that the socket required is deeper

Maybe a 12 pt head would be better?

I would think that a quality 6pt stubby socket would actually have less chance of rounding the head than an e-torx socket with poor engagement.

Either way i need to buy replacement bolts since these current heads don’t inspire confidence. Its either experiment with the mcmaster ones or play it safe with the OEM.

[bigjae46]

If you F-up the head you can use a size larger to get it off.

I'd do the same thing, just hasn't bothered me enough. I use an E12 on an impact swivel. Just did this! Built my 3.91 diff and installed it today.

[eacmen]

If you F-up the head you can use a size larger to get it off.

I'd do the same thing, just hasn't bothered me enough. I use an E12 on an impact swivel. Just did this! Built my 3.91 diff and installed it today.

Never thought you could use a larger socket. I’ll have to try that on the bench with these f-ed up bolts.

I tried the impact swivel and it would just bind against the trunk. Have you taken a hammer to that section or something?

Now that I think of it I think the previous owner used the low profile solid subframe bushings to offset the height of the plates. So maybe I just have less clearance than others…

[bigjae46]

No...I use a 12" extension.

[sapote]

I used a 3/8" x 9/16" adapter on the E14 socket, and a closed end 9/16 wrench and extension tube for this to break it loose. Don't back the bolt out too far or the socket/adapter will be trapped by the trunk.

[eacmen]

I used a 3/8" x 9/16" adapter on the E14 socket, and a closed end 9/16 wrench and extension tube for this to break it loose. Don't back the bolt out too far or the socket/adapter will be trapped by the trunk.

This is exactly what I did. Didn’t have enough leverage with the 9/16 tho. Double wrenched it, socket slipped and almost ruined the head.

[Casa de Mesa]

These were a PITA. However, my trunk floor was clearanced / hammered in a bit, much to my surprise. It was done by either BMW of Sterling VA when they replaced the diff under warranty (before my ownership) or Road Race Technologies (RRT) when they installed the Turner subframe plates.

With the *slightly* extra room, I was able to use a swivel and a torque wrench (which I hate doing...) to get it torqued down. In the future, I may just drop the subframe slightly.

[sapote]

This is exactly what I did. Didn’t have enough leverage with the 9/16 tho. Double wrenched it, socket slipped and almost ruined the head.

keeping the socket square on the bolt is the key.
Grind down the socket lip for lower profile.

[01SG]

I got those loose easy with a really thin, compact 3/8 Icon breaker bar from Harbor Freight, bought especially for that purpose for about $30.

Once they were out enough I grabbed the e-torx ratcheting Gearwrench.

[Arith2]

This style socket, I've noticed, grips e-torx really well. I can't find the 3/8 normal socket set I have online but this pass-through set would really be helpful. I have yet to see a tech using this socket or pass throughs because tool trucks just don't really sell them. I love them and they have made jobs like headers a breeze. I highly recommend getting this style socket and adding it to your tool box. Crescent is a good brand and should be sufficient. I have a craftsman set from before they went to china. Getting a ratcheting wrench to get the last few threads on these bolts would also be helpful. I'm constantly switching tools on tight bolts to make it easier. On this job, I used the "right" socket only for torquing and breaking loose.