Ring and Pinion life

Many of us have been discussing the alarming change in 9.5 ring and pinion life.

Back in 1993-4 there were some bad gears distributed and we actually went through a set every 3-4 runs for a short period of time. Then the problem solved itself.

In 2001-2005 I had several gear sets that lasted 100 runs. I finally took them out, mag'd them and found they were still fine. I stuck them in a box and put them on the shelf in the shop where they sit today.

Now with US Gears, 20-25 runs and they are junk. Some have reported as few as 11 runs without shake and they are absolute junk. The cracks are at the base of the pinion gear right at what I call the root. People have reported worse luck with Richmond Gears. One gear manufacturer claims to know nothing of the problem.

Because we were getting upwards of 100 runs from a 9.5 I never considered changing to a 10.5. I have been told 10.5's are a lot harder on transmission sprags. If it ain't broke, don't fix it...so I never did. But if this trend looks to be a permanent one I may need to make the switch.

Anyone else care to weigh in on this. My last gear set lasted 26 runs. When I took it out to inspect it, it was obvious that run 27 would have been disasterous.

RG

 

we run pro mod type car at near 2800 lbs. was hearing noise in rear pulling back to the pits after run. pulled it apart and every pinion tooth had cracks and most of ring gear teeth were cracked. it looked like it would have scattered the next run. we had 19 runs on that set of gears. called Mark Williams and ask about short life of gears and they said that was about what they were seeing. I know racing is rough on parts but it seems they should last a little better.

 

10.5" rear

Randy; forget the story you heard about the 10.5" rear causing sprag problems. I've have done much research into that story that got way worse every time you heard it.
The original fellow that had the problem will probably now say that getting rid of it had nothing to do with his sprag problem, at least I hope he would. It was two cars, ONE guy (same guy), and unfortunately switching cars and rear housings has not cured his bad luck.
Std. disclaimer:
I'm just a welder...........

 

we have run a chrisman rear 10.5 it has 132 runs. we look at it every 35 passes no problem with it. maybe the big gear is the answer. works for me. tasca ford ta\fc

 

Ralph:

Check your PM's.

Randy

 

i have ben hearing about a "tom's ring and pinion" company that makes a 10" ring and pinion that will fit in a 9.5" drop out center. the pro mod guys swear by it and their cars weigh almost 500 lbs more than a funny car. here is a link. http://www.tomsdifferentials.com/

 

A lot of it has to do with proper set-up. We have been runnung Motive Gear 9.5". Early in the season we had 2-sets that only got 2-3 runs before junk! OUCH! I can't tell you how many runs are on the set in the car now and we have a complete spare in the trailer that I hope stays there. It was all in set-up. I have even had several runs shaking all the way through 1st gear on the one in the car now. I am interested in learning more about this 10" gear though????

 

Randy

Check your PM

Mike

 

Yes, and take a look at their billet center section too. The gears & center are both under the 9" Ford section.

 

And a hell of an excellent welder you are my friend.......Happy Trails, Larry...Oh, did ya drink any beer in Hawaii or was it all Foo Foo drinks with the little umberella ?

 

No umberellas for me, just a 18 pack of pot belly control, Mick Ultra, 5 golf courses, 1 drag strip (for research purposes- tax category) and for the third time, a rental car full of roaches. Gotta love Maui!

Bob