Torx or Torx Plus?

[PKile]

To All,

I changed out the serpentine belt idler pulleys on my E46 BMW with the M54 engine over the weekend. It was a straightforward job, although I ran into a minor issue with my Lisle Torx driver bits. BMW uses what appear to be Torx fasteners on a couple of the idlers, as well as an offset Torx socket on the A/C pulley bracket to release tension on the belt.

My issue was the T55 driver was too large for the fasteners, yet the T50 driver (the next smaller size) had a lot of slop, but worked well enough to do the job. Could they be using Torx Plus in this application, and could that be the root of the problem?

Thanks in advance,
Paul

 

[Wakefield]

I cannot tell with the smaller fastener/socket sizes by looking whether they are Torx or Torx+. I wonder whether it is a good idea to try both Torx and Torx + bits for fit before deciding which one to use? Also use a magnifying glass and a bright flashlight to look at the fastener? I guess some kind of BMW shop manual should have a specification

 

[wagzilla]

on the bmws for the front idlers torx plus stubbie not much room to work, hope that helps
did you check it with a mirror and flash light not a allen head

James

 

[logikal]

Its a T55....I dont know what kind of tool your using to not fit but Im looking at one as we speak on a e91.

 

[d.mcfarland]

Torx and Allen head have to be cleaned out or the fit is never the best. At least that's what I've found.

 

[logikal]

The torx slot is a through hole. No way for it to be clogged. Well I won't say no way......

 

[logikal]

is this the tensioner?

 

[PKile]

is this the tensioner?

Yep, that's the A/C belt tensioner. After checking my old one on the bench tonight, turns out the hole for backing off the tensioner is a T60 Torx, there is also a bolt under the plastic cover on the pulley that is a T50 Torx. The T50 has a little slop, but was still usable.

BTW, that must be a later installation, because the installation bolt on mine was a 16mm hex head, not an e-torx like the one in your picture.

Thanks for all your help, guys. I may end up getting a set of Torx Plus drivers, because I am sure I will run into them sooner or later.

Cheers,
Paul