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Topic Review (Newest First)
04-27-2011 07:36 AM
LS1-IROC
Quote:
Originally Posted by 96lt4c4
I set it up last night and it clears the case but was hitting the billet cap. A flapper wheel on my grinder took care of that, no big deal at all. I didnít have to remove much material. I would rather have some off the cap than a bunch off the posi. Still getting some run out on the ring gear though. I check both ring gear mating surfaces, spinning the posi and using a dial indicator and it is dead straight. It has to be coming from this ring and pinion. I go from one thing to another. My back lash is varying about .002 around the ring gear. What is acceptable? I know going through this I have had some with no run out. This is a new Motive performance 3.89 gear. I am thinking about sending it back to Summit and trying another one.
My motive R&P has .003 runout....I'm running it that way currently. I use up the recommended tolerance for backlash with it being like this.
04-22-2011 07:27 AM
96lt4c4
Quote:
Originally Posted by prostreet6t9
If I was getting a .002 run out I would set the backlash at 8 at the tight spot putting you at 10 on the loose side,and check patterns.
The pattern looked OK I guess, I am sending it back to Summit and getting another RP. Thats one thing I like about buying this stuff from them is they will take it back no questions asked.
04-21-2011 09:14 AM
prostreet6t9
Quote:
Originally Posted by 96lt4c4
I set it up last night and it clears the case but was hitting the billet cap. A flapper wheel on my grinder took care of that, no big deal at all. I didnít have to remove much material. I would rather have some off the cap than a bunch off the posi. Still getting some run out on the ring gear though. I check both ring gear mating surfaces, spinning the posi and using a dial indicator and it is dead straight. It has to be coming from this ring and pinion. I go from one thing to another. My back lash is varying about .002 around the ring gear. What is acceptable? I know going through this I have had some with no run out. This is a new Motive performance 3.89 gear. I am thinking about sending it back to Summit and trying another one.

If I was getting a .002 run out I would set the backlash at 8 at the tight spot putting you at 10 on the loose side,and check patterns.
04-21-2011 07:38 AM
96lt4c4
Quote:
Originally Posted by prostreet6t9
Thats pretty common actually. Sometimes customers are hard to figure out and will gripe if they have to clearance the case if a thick hat is used. Other customers are fine with it. I personally always use the thick and do some grinding if needed.

I set it up last night and it clears the case but was hitting the billet cap. A flapper wheel on my grinder took care of that, no big deal at all. I didnít have to remove much material. I would rather have some off the cap than a bunch off the posi. Still getting some run out on the ring gear though. I check both ring gear mating surfaces, spinning the posi and using a dial indicator and it is dead straight. It has to be coming from this ring and pinion. I go from one thing to another. My back lash is varying about .002 around the ring gear. What is acceptable? I know going through this I have had some with no run out. This is a new Motive performance 3.89 gear. I am thinking about sending it back to Summit and trying another one.
04-20-2011 12:51 PM
prostreet6t9 Thats pretty common actually. Sometimes customers are hard to figure out and will gripe if they have to clearance the case if a thick hat is used. Other customers are fine with it. I personally always use the thick and do some grinding if needed.
04-20-2011 09:00 AM
TimoFinn Why in the world would they take material off that place,that`s prone to cracking
I ordered my strange rear with the billet half posi for that reason.
04-19-2011 07:51 PM
96lt4c4 Got the posi tonight and was suprised at what I found. The Yukon and Ford Racing are the same posi. If you look on Yukons website the part number is the same as the part number on the Ford Racing posi that I just got from Summit Racing. When comparing the two units something just didnt look right....







The one on the left is the new one. Why in the hell would Quick Performance send my a posi with half of the hat machined off? From what I can tell there should be no clearence issues with the aluminum case. Even if there is I would much rather grind on the case a little then cut half the material off the side of the posi and make it weak. I thought the machine job on the posi looked like crap. I could tell that someone had put it in a lathe and turned it down. Now I can see how much they took off, and its a bunch! I am begening to wonder if the posi was flexing. Crazy.....
04-19-2011 08:30 AM
96lt4c4 Well, after all the checking on the posi, I still have a lot of run out on the ring gear. I think I have wore the area that the ring gear presses on to. I can put the ring gear on by hand, its not a press fit anymore. My new posi will be here today, hopefully that will fix it.
04-16-2011 06:32 AM
96lt4c4
Quote:
Originally Posted by prostreet6t9
Your welcome Hopefully that was the problem. Like 302 says.... walk away for a bit

It has to be, I kept wondering where the metal was coming from. If you listen to the Youtube video at about 1:50 my phone falls between the back seat and the tunnel and you can hear metal to metal grinding sound. I am pretty sure that is what it is, it obviously isnt a good thing that they were hitting. One side was hitting bad enough to gall the block pretty good.

Anyway I took the posi to work with me yesterday. Luckilly I have accsess to some pretty cool tools. I spun the 2 halves of the posi in a lathe and checked for runout, we also have a machined flat slab of granite the is 10 foot long and 3 feet thick. I layed the 2 halves on the granite and tryed to slide a .001" shim stock underneath and it wouldnt go. The posi checked out fine. The only thing I found was that the threw bolts on the Yukon case were bent. I have a N Strange case that I am going to try.
04-15-2011 05:45 PM
LS1-IROC I've read through most of your post....I too am fighting some noise in my 9" in my IROC. I have not gone through all the steps you have, but I have played around with it quite a bit. I did not see if you said you checked for ring gear run-out. I have .003 runout on my ring gear when torqued to the Trac-loc posi. I beleive this is what my issue is. I have got it to the point where it's pretty quiet now...only whines between 50-70 mph on accel...quiet all the time on decel. Good luck with it!
04-15-2011 02:41 PM
prostreet6t9
Quote:
Originally Posted by 96lt4c4
Thanks to prostreet6t9, I have finally found it. Just goes to show when you think things are right sometimes you just need to go back and double check.
Axels were too long and hitting inside the posi. I measured wrong. I bottomed my tape against the pin in the posi and I should have been clipping it on the side gears. I put everything in the old ford center section, stuck it in the housing and re measured. Both axels were a 1/16th too long. Just that little bit was causing it to hit the block in the center of the posi. I ground a good 1/16th off each axel and re taperd them by hand. They turned out pretty good.

I set up my new ring and pinion in the aluminum housing and now I think the posi is bent somewhere, the pattern was moving up and down the tooth as I spun it.



I am so burnt out on this thing that now even though I am pretty sure this is whats wrong with it, I do not want to work on it.

prostreet6t9, Thank you sir, I owe you a beer.
Your welcome Hopefully that was the problem. Like 302 says.... walk away for a bit
04-14-2011 08:00 AM
AutoGear Im worn out just reading along for the past 8 pages. Im proud of you though, seriously. Its awesome to see someone fight through this stuff and MAKE it right.

Things like this are part of the reason why we build cars with our hands, not our checkbooks.
04-14-2011 07:36 AM
302 Z28 That is a real bummer, walk away from it for a week or so.

Vince
04-14-2011 06:57 AM
96lt4c4 Thanks to prostreet6t9, I have finally found it. Just goes to show when you think things are right sometimes you just need to go back and double check.
Axels were too long and hitting inside the posi. I measured wrong. I bottomed my tape against the pin in the posi and I should have been clipping it on the side gears. I put everything in the old ford center section, stuck it in the housing and re measured. Both axels were a 1/16th too long. Just that little bit was causing it to hit the block in the center of the posi. I ground a good 1/16th off each axel and re taperd them by hand. They turned out pretty good.

I set up my new ring and pinion in the aluminum housing and now I think the posi is bent somewhere, the pattern was moving up and down the tooth as I spun it.













I am so burnt out on this thing that now even though I am pretty sure this is whats wrong with it, I do not want to work on it.

prostreet6t9, Thank you sir, I owe you a beer.
04-13-2011 01:07 PM
96lt4c4

This is one of the Carrier bearing races that just came out. Really uneven wear pattern.
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