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Discussion Starter #1
Took some pictures of my diff, trying to figure out whats going on with it. thought that I would share what it looks like inside there. Nothing much to look at really, looks like a simple setup.





 

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Does anyone know what size the ring and pinion is. What Dana do we have. I know GM makes a 7.5 7.6 8.2 8.5 in the 10 bolt housing and the 12 bolt rear uses a bigger ring gear. I think its 8.875. This might be helpful information to determine horse power/torque ratings of the stock rear. In case any one is interested to find out how strong a 7.5 rear is, I have a 77 Monza with a 383 stroker 373 gears turbo 350 trans and 3000 stall converter with slicks running 12.50 at 109 MPH 1.86 60 FT-------danfigg
 

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I worked for Dana 22 years, I have seen inside umpteen hundreds of carriers. (Mack Truck) There is an art to building them. There are very strict tolerances that if not adhered too well, does rear end whine ring a bell? Jigs are made to eliminate the constant micrometer measuring sometimes if the jig isn't positioned properly crap happens. Sometimes its the parts not coming from the vendor correct. I have seen this hundreds of times, Bull gears not right etc sent back to vendor. Sometimes they get through. Inspectors will randomly tear apart a carrier and go over it not every one is inspected.

The white paint you see on gears is there for a reason. The gear is marked to measure rotation to assure all gears are properly meshing.

I knew guys who could build these in their sleep. Excellent builders who were required to build x amount a day. We had cells and each builder was required to build a certain amount. They would work as fast as possible to they had more time at the end of the day for some slack time. This replaced the assembly line routine that gets really mundane and your mind wanders and more mistakes are in general, made. Still, the faster you work the more prone you are to making mistakes.

Then there are those who build with I don't really care attitude. The better the employer treats you the more you are inclined to put out better.

Despite it all crap happens I still don't know exactly what the cause of the rear end whines on these cars were a result of, I have heard theories but no definitive reason. What looks simple in the carrier is actually more complicated than you think.
 

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Discussion Starter #4
I talked to a local guy yesterday about my diff issues. He has pretty good knowlage of our cars and diffs. He talked to a guy at Dana and he had explained to him the issues with our diffs. He told me that, the issues with the diffs are more of a manufacturing issue than a parts issue. Whatever been going on with Dana and our diffs is why we have issues with them. I know Dana make some damn good diffs but when it comes to our cars its hit and miss. This is my second diff and I'm not impressed with the craftmanship of them. I was told that these diffs are finiky so finding the correct fluid that will not cause problems with them is the key also.

I ordered some Torco w/Type F fluid, hopefully it will be in before the weekend so I can see will that get rid of the clunking. The howl is a different issue that may be gears or pinion bearing going bad. I was told the stock gear set is around $600-$700:eek: I also didn't know that stock GM gear sets are 3.73 & 3.91. Also there are other gearsets available I think he said 3.07 and 3.27.

I also absorbed from him that he has a 700hp GTO manual on stock driveshaft and diff w/the Harrop cover and Detroit Truetrac. He said most of the issues with people braking stuff in the drivetrain is folks that don't know how to drive. The wheel hop is the major issue with braking drivetrain components.
 

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I talked to a local guy yesterday about my diff issues. He has pretty good knowlage of our cars and diffs. He talked to a guy at Dana and he had explained to him the issues with our diffs. He told me that, the issues with the diffs are more of a manufacturing issue than a parts issue. Whatever been going on with Dana and our diffs is why we have issues with them. I know Dana make some damn good diffs but when it comes to our cars its hit and miss. This is my second diff and I'm not impressed with the craftmanship of them. I was told that these diffs are finiky so finding the correct fluid that will not cause problems with them is the key also.

I ordered some Torco w/Type F fluid, hopefully it will be in before the weekend so I can see will that get rid of the clunking. The howl is a different issue that may be gears or pinion bearing going bad. I was told the stock gear set is around $600-$700:eek: I also didn't know that stock GM gear sets are 3.73 & 3.91. Also there are other gearsets available I think he said 3.07 and 3.27.

I also absorbed from him that he has a 700hp GTO manual on stock driveshaft and diff w/the Harrop cover and Detroit Truetrac. He said most of the issues with people braking stuff in the drivetrain is folks that don't know how to drive. The wheel hop is the major issue with braking drivetrain components.
With the ISO requirements Dana was so hyped on at one time one of the procedures was to have a step by step build requirements at stations and they were to build in accordance to the ISO guidelines or they risked losing their ISO standing. Also winning Malcolm Baldrich awards meant a lot. We were required to undergo 40 hours of training each year to keep up with technology and maintain standings within the ISO community etc.

With these rears something went wrong. Not too long ago Dana almost went under, they filed for bankruptcy froze wages upped medical out of pockets to its employees (non union) they were under a hostile takeover at one time by I think Arvin Meritor. Dana restructured closed hundreds of plants laid off thousands of people, downsized drastically and entered into a partnership with the UAW to save them. Dana is now 100% UAW at one time DANA spent millions to fight unionization. All a Dana plant had to do now was show a 50%+1 card check and they are in Dana agreed not to challenge. Not saying union has anything to with quality concerns but the times at DANA changed from wayyyyy back.

By partnering with the UAW Dana survived they came out of bankruptcy and the hostile takeover bid was thwarted. I have been out since 2006 so I only get bits and pieces but Dana is NOT what they used to be. Dana MANY years ago was the #1 supplier of parts to the auto industry. With CEO changes well, the company went to hell in a hand basket. It all trickles down to the working stiff. Quality ain't what it once was.
 

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Discussion Starter #6
Does anyone know what size the ring and pinion is. What Dana do we have. I know GM makes a 7.5 7.6 8.2 8.5 in the 10 bolt housing and the 12 bolt rear uses a bigger ring gear. I think its 8.875. This might be helpful information to determine horse power/torque ratings of the stock rear. In case any one is interested to find out how strong a 7.5 rear is, I have a 77 Monza with a 383 stroker 373 gears turbo 350 trans and 3000 stall converter with slicks running 12.50 at 109 MPH 1.86 60 FT-------danfigg
Our diffs are not that bad, IF built correctly they are one of the last things that break in the drivetrain.
With the ISO requirements Dana was so hyped on at one time one of the procedures was to have a step by step build requirements at stations and they were to build in accordance to the ISO guidelines or they risked losing their ISO standing. Also winning Malcolm Baldrich awards meant a lot. We were required to undergo 40 hours of training each year to keep up with technology and maintain standings within the ISO community etc.

With these rears something went wrong. Not too long ago Dana almost went under, they filed for bankruptcy froze wages upped medical out of pockets to its employees (non union) they were under a hostile takeover at one time by I think Arvin Meritor. Dana restructured closed hundreds of plants laid off thousands of people, downsized drastically and entered into a partnership with the UAW to save them. Dana is now 100% UAW at one time DANA spent millions to fight unionization. All a Dana plant had to do now was show a 50%+1 card check and they are in Dana agreed not to challenge. Not saying union has anything to with quality concerns but the times at DANA changed from wayyyyy back.

By partnering with the UAW Dana survived they came out of bankruptcy and the hostile takeover bid was thwarted. I have been out since 2006 so I only get bits and pieces but Dana is NOT what they used to be. Dana MANY years ago was the #1 supplier of parts to the auto industry. With CEO changes well, the company went to hell in a hand basket. It all trickles down to the working stiff. Quality ain't what it once was.
How many factories does Dana have?
I don't know how long was the Dana rear end used in the V platform, but it was long before we got them as the GTO here in the states. The V platform was part of a modified Opel Omega/Cadillac Catera. I'm not sure was the same Dana used in thoes cars also.

But Dana was the rear end to have in anyones vehicle. When I was "growing up" with cars I wanted a Dana because it was the Turbo 400 of diffs.
 

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Our diffs are not that bad, IF built correctly they are one of the last things that break in the drivetrain.


How many factories does Dana have?
I don't know how long was the Dana rear end used in the V platform, but it was long before we got them as the GTO here in the states. The V platform was part of a modified Opel Omega/Cadillac Catera. I'm not sure was the same Dana used in thoes cars also.

But Dana was the rear end to have in anyones vehicle. When I was "growing up" with cars I wanted a Dana because it was the Turbo 400 of diffs.
I honestly don't know how many are left I would be guessing. I do know they closed many I don't know the numbers.

They are a global company maybe their website can answer your question.
 

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Discussion Starter #8
Well I got rid of the clunking so far. As advised from another source, I was told to try Torco and Torco type F(Ford) friction modifier. So I did, I ordered two quarts of Torco 75W-140 and a bottle of Torco's Type F friction modifier. Got it in about two days, got rid of the Royal Purple filled it with the Torco. Drove it around base for about 10-15mins figure 8's and tried to do some burn outs but that didn't work out too well, I have alot of wheel hop. Diff seems to be doing well. But the faint howl is still there 45-60mph under accel stedy state driving. So that tells me the gears could be jacked. Ohh well, I'll live with it for alittle untill I get it fixed or it gets worse.

What was explained to me the Torco has type G for GM cars and Type F for Ford cars. The Type G is for clutch type LSD's and Type F is for cone type LSD's. Sence the GTO has cone type set-up you'll use Type F.
 
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