With all the diff threads popping up, I have been thinking.

Our diff's are strong internally for the most part. I say this b/c you see guys making 800whp+ on the dyno w/o them blowing themselves apart. However, get it on the street, and they go ka-boom. The biggest issue is wheel hop, which most IRS cars suffer from it seems. The issue as I see it, is the rear end rotating upward on launch thus increasing the pinion angle (where the driveshaft enters the diff) and putting increased pressure on the collar bearing and breaking it, thus grenading the rear end.

So how do we prevent that?

Why not build a brace that connects to the diff and the frame. This would prevent it from rotating upward under heavy acceleration/launching. Muscle cars have been doing this for years, cross braces/ladder bars/etc. It's not a new concenpt, just new to the s2k community.

Simply build a bracket that looks like a C, that bolts to the center housing, and using a helm joint that would connect to the frame/etc and prevent any motion of the differential.

Thoughts?

 

sounds like a great idea, in theory it could save a lot of money and downtime

 

Interesting. Should see if Puddy would get in on this.

 

it wouldnt hurt to try!

 

We used the same thing sort on mustangs. I put what we called a pinion snubber on the housing that would stop the housing from rotating upward. Just a large bushing that pressed against housing right behind the driveshaft flange. Worked great on a stang, something similar should work well on our cars. When I was building my rock crawler we also welded heavy trusses to the housing to strengthen them from twisting under the weight of huge tires. I wonder if trussing the housing would help, our diffs are certainly not the beefiest things.

 

Exactly, my buddies with mustangs and ls1 cars are well aware of these types of "fixes".

do you have any pics of the bushings you are referring to?

 

that still doesnt fix the craptastic housing.. you'll still bust the bearing caps.

That being said.. I will be doing something of this nature with my ford 8.8. The front mounts are too far forward to really keep the front of the diff from lifting up. I will probably weld in an extra tube to the subframe and have the diff mount straight to that instead of the stock bushings.

 

When i had my 350z, i purchased solid diff bushings and that Brace you speak of. It tighted up the diff. But mainly due to the stiff diff mounts...not the brace.

Swapping out the mounts to solid mounts is the same if not more secure than just a brace. At least the mounts would cover 4 corners of the diff vs just a Brace on one bolt or cent of the diff.

 

No pics sorry. It was just a cone shaped piece of urothane on the end of an adjustable mount. You could position the bushing where you wanted the housing to stop rotating. Very simple piece. Was very effective at stopping wheel hop.

 

I agree on the housing. The stock diff in our car split in half, but the ring and pinion was mint. The problem is the gear separation under high load that tends to put pressure on the weak case.