Front Drive Shaft Loop Modification w/4" Drive Shaft

[tmcolegr]

I recently worked on (2) S197 GTs (08 & 09), neither one was mine, that had 4" one piece drive shafts installed. Same complaint with both vehicles - rubbing or scraping noise under hard launch. Common to both vehicles was the Metco front DSL.

I've run into this before as I use the Metco front DSL whenever possible for 1 reason: it doesn't require the front of the drive shaft to be removed to install as the loop is a separate piece from the support. However with a 4" shaft the loop needs to be spaced away from the support so as not to rub the larger 4" drive shaft. This problem is worse if using lowered motor mounts or a K-Member with lowered mounts as it tilts the rear of the transmission up and further reduces clearance between the drive shaft and loop.

Here's a picture of BMR's redesigned front DSL for 2011 GTs.

Notice the clearance between the top of the loop and OEM drive shaft. Now imagine how that clearance would be reduced if using a 4" drive shaft. BMR even mentions using a spacer between the loop and the support with their new DSL to prevent this rubbing.

So if you're using a Metco front DSL and a 4" drive shaft you may want to consider fabricating a spacer similar to the one I have included in the attached drawing. While I haven't installed one of BMR's new 2011 front DSLs, the spacer would be very similar.

PS: I sure would like to see BMR redesign the front DSL for 2005-2010s to be have the same design as their DSL for 2011 GTs.

 

[gil_t2]

I use the BMR 010 dsl, with 4" DS. But the compresson end of the DS is in the front so it is only 3 3/4" . Also made spacers to drop the trans mount, when i dropped the engine mounts. Only problem I don't like that I need to unbolt the DS if I want to remove the loop.

 

[tmcolegr]

Only problem I don't like that I need to unbolt the DS if I want to remove the loop.

That is exactly what I told Kelly @ BMR

 

[tmcolegr]

Here's pictures of the fabricated spacers, longer grade 8 bolts, hardened washers & lock nuts

Spacers installed under the loop

Notice the clearance now between the inside of the loop and the top of the 4" drive shaft

 

[white05gt]

I don't feel so bad now, I thought I was the only one with Cat hardware on my car.

 

[tmcolegr]

I don't feel so bad now, I thought I was the only one with Cat hardware on my car.

Good observation. Cat hardware is the best!!