Do these things help at all?

 

 

IMO they are a must. I have went threw 2 rears in my car so far the first one was without one. the 2nd one the posi went out but the gears were fine.

 

Is your car currently using the 10 bolt and running 11.11? Are you automatic? If so, how much stall? Thanks,
Chris

 

Yes it is. I have a 4L60E and a midwest 3,200 stall. Best 60ft so far is a 1.53

 

I would definitely go with a solid pinion spacer. I have never installed a crush collar before, but the solid spacer method is an easy install. It is just tedious because you have to keep shimming it and measuring it until the drag torque is just right. Just looking at the stock crush collar and then looking at the solid spacer, its no contest. For an extra $20, its piece of mind when I launch

 

So,
Will a 10 bolt with good gears, girdle, posi, studs, and solid spacer survive a 383 with 3200 stall for a while? I am estimating 11.80's or so.
Thanks!

 

I don't think the 10 bolt will hold up for long. I have been wondering about the pinion spacer also. I have a moser 12 bolt in mine. Made my first 4 runs on it 2 weeks ago since installing it this summer. I was launching at 3500 on the bottle with ET streets. Pulled 1.6 60ft times all 4 runs but ended up twisting the splines on my Denny's drive shaft. I upgraded to a billet yoke and Denny is building me a new shaft at no cost. No damage to the shaft, just the yoke. But along with that, the rear is whining on deceleration, which indicates the pinion. I'm suspecting that my pinion set up went out, so think i'll have to up to a pinion spacer. Kinda ticks me off cause you figure Moser would just put one it if your spending over two grand on a complete rear. Why not just add the $20 part?! Which brings me to a question, how do I go about installing the spacer? I know how to take the rear apart, but how to I set it back up?

Ken R.

 

If your installing it in a rear that is already "setup" you can measure the "crush sleave" and then use the shims with the solid pinon suport to make it the same.

And if you have a A4 trans running in the 11's on a 10 bolt shouldn't be any big deal. I mean you might break one every now and then but look at the options spend 2-400 to rebuild it or 2,3-600 to put in a stronger rear.

 

i am working on some made out of bushing steel, the ratech one will only take about 250 ftlb of torque and then it conformes to the pinion and wont hold so i have talked to a local machinst and he's gonna made me up about 10. but these will be grind to fit so there wont be any shims.

 

Sounds like a good idea. I have not had an issue with the ratech one. But I do see your point.

 

As far as gears go, is that area under the solid spacer the weak point? Or, is the whole gear/pinion weak and t his is just a way to strengthen at least one part of it. Also, I heard the 3.73 gear was stronger than the 4.10 one because the pinion had more teeth. Is this true that it is stronger?

 

When I had my 4:10's installed in my old 10 bolt I had them use a solid pinion spacer. I would say they are must for the 10 bolt as well. I made 70-80 passes on it with an M6, drag radials and rwhp between 300-355 for those runs. Also used a rear support cover with preload studs and a stud kit. I ran into the low 12's with it and mine held up pretty well, it did whine a bit after the first 5-10 passes but not too bad. That was on an SLP clutch which is fairly soft hitting. I went to the 9" because I wanted to go with a stronger clutch and I know it would have eventually killed the 10.

 

There is no one weak point. I have heard of people breaking everything from axles to rings or pinions to carriers. The bottom line is the 7.5" rear is just not beefy enough to relieve a satisfactory amount of stress. That is not to say they are weak though. If the rear is set up correctly as GREGG 97Z stated, it will last for awhile.

As far as a 3.73 being stronger than a 4.10, I am not sure. But I will say that your logic is backwards. If a 3.73 has more teeth, then it is WEAKER. More teeth equals less material, therefore the less teeth, the stronger the gear. Maybe that is what you were trying to say and I misconstrued your words. I know that many people discuss a 4.11 vs 4.10 for this reason - a 4.11 has less teeth and is consequently stronger, but it is harder to find that ratio for 7.5" rears. I would not pick a 3.73 over a 4.10 just for strength issues, if that was even the case.

 

Correct me if I'm wrong doesnt the 3.42, 3.73 and 4.10 all use the same ring, 41 teeth, just different pinion, 12, 11 & 10 teeth. 4.11's are 37r and 9p so yes less teeth, more meat, so hopefully stronger