Replaced Clutches in Dana 70 Differential
05-06-2007, 07:20 AM
#1
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Replaced Clutches in Dana 70 Differential
Pulled Dana 70 Limited Slip Differential, more out of curiosity than need, to see wear and tear after 125,000 miles. Wanted to restack clutches & steels for 'full' limited slip.... and also find out if it's a Power-Loc limited slip (as Dana says, based on the BOM #) or a modified Trac-Loc, as reported here by many members.
MISINFORMATION-
1-"Power-Loc (preferred LSD) was discontinued by Dana in 1998." I found many threads claiming this fact. Believe it's true for the Dana 80 (manual trannys) but it's not true for my 02 Dana 70. It is a FULL Pwr-Loc, with curved steel plates and an oval groove with 'V' bottom, housing the floating cross shaft. (See pic below)
2-"Not all clutches & plates are alternately stacked". They were on mine. It's just the Dana 80's that aren't.
3-My 02 Service Manual is wrong. None of the descriptions or diagrams matched what I found when I got inside the differential?? (Major thanks to Diesel Dan, from FASS Co, for his help. Nice to have someone that's been there and done that before).
I bgt a rebuild kit , in case needed, from Dan at "Quad 4x4" out of Roberts, Mt. He really knows his stuff and the kit is a good price compared to many others I found.... comes with all new clutches/steel disks, axle gaskets, friction modifier (to pre-soak new clutches), and even 6 ml of LockTight blue for axle bolts & Permatex for axle seals!
Web site for QUAD 4X4 located HERE
Found heavy wear on one clutch and one steel plate (see pic below) but all drive units and metal to metal surfaces were impressively like new! I don't do heavy towing but do haul heavy often (up to 10,000 lbs) and drag race 10 to 12 times a yr. I find the Dana 70 an impressive rear end.
Took 3-3.5 hrs first time (some breaks for rain). Could easily do it again in 2 hrs.
DEFINATELY A POWER-LOC... RAMPING TYPE, FLOATING CROSS SHAFT
CLUTCH MATERIAL WORN OFF ONE OUTER DISK
ONE SIDE APART
ALL APART
MISINFORMATION-
1-"Power-Loc (preferred LSD) was discontinued by Dana in 1998." I found many threads claiming this fact. Believe it's true for the Dana 80 (manual trannys) but it's not true for my 02 Dana 70. It is a FULL Pwr-Loc, with curved steel plates and an oval groove with 'V' bottom, housing the floating cross shaft. (See pic below)
2-"Not all clutches & plates are alternately stacked". They were on mine. It's just the Dana 80's that aren't.
3-My 02 Service Manual is wrong. None of the descriptions or diagrams matched what I found when I got inside the differential?? (Major thanks to Diesel Dan, from FASS Co, for his help. Nice to have someone that's been there and done that before).
I bgt a rebuild kit , in case needed, from Dan at "Quad 4x4" out of Roberts, Mt. He really knows his stuff and the kit is a good price compared to many others I found.... comes with all new clutches/steel disks, axle gaskets, friction modifier (to pre-soak new clutches), and even 6 ml of LockTight blue for axle bolts & Permatex for axle seals!
Web site for QUAD 4X4 located HERE
Found heavy wear on one clutch and one steel plate (see pic below) but all drive units and metal to metal surfaces were impressively like new! I don't do heavy towing but do haul heavy often (up to 10,000 lbs) and drag race 10 to 12 times a yr. I find the Dana 70 an impressive rear end.
Took 3-3.5 hrs first time (some breaks for rain). Could easily do it again in 2 hrs.
DEFINATELY A POWER-LOC... RAMPING TYPE, FLOATING CROSS SHAFT
CLUTCH MATERIAL WORN OFF ONE OUTER DISK
ONE SIDE APART
ALL APART
05-06-2007, 07:55 AM
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MISINFORMATION-
1-"Power-Loc (preferred LSD) was discontinued by Dana in 1998." I found many threads claiming this fact. Believe it's true for the Dana 80 (manual trannys) but it's not true for my 02 Dana 70. It is a FULL Pwr-Loc, with curved steel plates and an oval groove with 'V' bottom, housing the floating cross shaft. (See pic below)
2-"Not all clutches & plates are alternately stacked". They were on mine. It's just the Dana 80's that aren't.
1-"Power-Loc (preferred LSD) was discontinued by Dana in 1998." I found many threads claiming this fact. Believe it's true for the Dana 80 (manual trannys) but it's not true for my 02 Dana 70. It is a FULL Pwr-Loc, with curved steel plates and an oval groove with 'V' bottom, housing the floating cross shaft. (See pic below)
2-"Not all clutches & plates are alternately stacked". They were on mine. It's just the Dana 80's that aren't.
05-06-2007, 10:05 AM
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sweet. appearently some made it though and got good equiptment. thats interesting to know about the d70.
since ive got a handful of garbage d70 trac-lok housings that i need to toss from later model trucks. lm glad to know that some made it out with good equiptment.
since ive got a handful of garbage d70 trac-lok housings that i need to toss from later model trucks. lm glad to know that some made it out with good equiptment.
05-06-2007, 10:35 AM
#4
Registered User
Rowland & Dan rock for doing that rear outside in the rain! 
Good news/bad news for me, though - now I'm sure the '98 came with a PowerLoc, but I'm wondering if Dana sent us the service replacement TracLoc a few years back when I blew a spider gear through the diff cover?
Good news/bad news for me, though - now I'm sure the '98 came with a PowerLoc, but I'm wondering if Dana sent us the service replacement TracLoc a few years back when I blew a spider gear through the diff cover?
05-06-2007, 10:14 PM
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just about to pull mine apart, do you have the torque spec's for the case bolts? How well did the rebuild work for you? any pointers sure would help thanks
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05-07-2007, 07:28 AM
#8
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Thread Starter
Bearing Caps/ - 80 ft-lbs
Differential Cover - 35 ft-lbs; Mag Hy-Tec w/ O-ring - 25 ft-lb max
Axle Shaft Bolts - 95 Ft-lbs
Originally Posted by LanceD
I think the reason the 80s are not alternately stacked is because there is a lot more plates and clutches in them.
Originally Posted by ddestruel
....appearently some made it though and got good equiptment. thats interesting to know about the d70.
Anyone interested...it's easy to check (say when changing gearlube) by just removing the cover.
RJ
05-07-2007, 07:43 AM
#9
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Thread Starter
Keep everything side specific.... what comes off the left goes back on the left. Lay parts out in order and reassemble with new in reverse order. Bearing Caps are side specific AND top & bottom specific.
Soak clutches & plates well. I misread and only soaked clutches. After reassembly...had some scary dragging noise for first hr. when turning. Thought, for awhile, we mis-assembled, but it cleared up after drive on interstate with fluid heating up and splashing around.
Extra set of hands are very helpful getting differential in & out of case. Those suckers are heavy in tight spaces.... would guess 70 lbs.
Good Luck
RJ
05-07-2007, 08:06 AM
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Pulled Dana 70 Limited Slip Differential, more out of curiosity than need, to see wear and tear after 125,000 miles. Wanted to restack clutches & steels for 'full' limited slip.... and also find out if it's a Power-Loc limited slip (as Dana says, based on the BOM #) or a modified Trac-Loc, as reported here by many members.
MISINFORMATION-
1-"Power-Loc (preferred LSD) was discontinued by Dana in 1998." I found many threads claiming this fact. Believe it's true for the Dana 80 (manual trannys) but it's not true for my 02 Dana 70. It is a FULL Pwr-Loc, with curved steel plates and an oval groove with 'V' bottom, housing the floating cross shaft. (See pic below)
2-"Not all clutches & plates are alternately stacked". They were on mine. It's just the Dana 80's that aren't.
3-My 02 Service Manual is wrong. None of the descriptions or diagrams matched what I found when I got inside the differential?? (Major thanks to Diesel Dan, from FASS Co, for his help. Nice to have someone that's been there and done that before).
I bgt a rebuild kit , in case needed, from Dan at "Quad 4x4" out of Roberts, Mt. He really knows his stuff and the kit is a good price compared to many others I found.... comes with all new clutches/steel disks, axle gaskets, friction modifier (to pre-soak new clutches), and even 6 ml of LockTight blue for axle bolts & Permatex for axle seals!
Web site for QUAD 4X4 located HERE
Found heavy wear on one clutch and one steel plate (see pic below) but all drive units and metal to metal surfaces were impressively like new! I don't do heavy towing but do haul heavy often (up to 10,000 lbs) and drag race 10 to 12 times a yr. I find the Dana 70 an impressive rear end.
Took 3-3.5 hrs first time (some breaks for rain). Could easily do it again in 2 hrs.
DEFINATELY A POWER-LOC... RAMPING TYPE, FLOATING CROSS SHAFT
CLUTCH MATERIAL WORN OFF ONE OUTER RING
ONE SIDE APART
ALL APART
MISINFORMATION-
1-"Power-Loc (preferred LSD) was discontinued by Dana in 1998." I found many threads claiming this fact. Believe it's true for the Dana 80 (manual trannys) but it's not true for my 02 Dana 70. It is a FULL Pwr-Loc, with curved steel plates and an oval groove with 'V' bottom, housing the floating cross shaft. (See pic below)
2-"Not all clutches & plates are alternately stacked". They were on mine. It's just the Dana 80's that aren't.
3-My 02 Service Manual is wrong. None of the descriptions or diagrams matched what I found when I got inside the differential?? (Major thanks to Diesel Dan, from FASS Co, for his help. Nice to have someone that's been there and done that before).
I bgt a rebuild kit , in case needed, from Dan at "Quad 4x4" out of Roberts, Mt. He really knows his stuff and the kit is a good price compared to many others I found.... comes with all new clutches/steel disks, axle gaskets, friction modifier (to pre-soak new clutches), and even 6 ml of LockTight blue for axle bolts & Permatex for axle seals!
Web site for QUAD 4X4 located HERE
Found heavy wear on one clutch and one steel plate (see pic below) but all drive units and metal to metal surfaces were impressively like new! I don't do heavy towing but do haul heavy often (up to 10,000 lbs) and drag race 10 to 12 times a yr. I find the Dana 70 an impressive rear end.
Took 3-3.5 hrs first time (some breaks for rain). Could easily do it again in 2 hrs.
DEFINATELY A POWER-LOC... RAMPING TYPE, FLOATING CROSS SHAFT
CLUTCH MATERIAL WORN OFF ONE OUTER RING
ONE SIDE APART
ALL APART
05-07-2007, 08:13 AM
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Extra set of hands are very helpful getting differential in & out of case. Those suckers are heavy in tight spaces.
RJ[/QUOTE]
Man that 80 was alot heavier than when i did my 70 a while ago.Specially when your sitting on a creeper by your self
RJ[/QUOTE]
Man that 80 was alot heavier than when i did my 70 a while ago.Specially when your sitting on a creeper by your self
05-07-2007, 08:56 AM
#12
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I just restacked the clutches in my Dana80 i just got, and there are 5 frictions and 7 steels on each side, only 2 frictions where stacked, and i believe they only stack two for the light dodge trucks so they wont chatter, cause the D80 is such a broadly used rear in heavy vehicles,where in a box truck or something they probably stack them all for that application. But in my 80 the plates dont have the friction like the 70's, they have grooves cut in the plates in different directions and i guess thats how they engage.
05-07-2007, 09:15 AM
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Just a comment fyi. I think that a d80 pl would have the same internals, clutch stack and parts, as the d70 pl pictured. I would bet that the rebuild kit has the same part number. I could allways be wrong but I wonder if the ring gear diameter is the only difference between the two. I am sure that that applies to detroit lockers and suspect it might be the same with pls as well. Does anyone know for sure? It would be nice to be able to just slot the ring gear holes and use a d70 pl in my traction challanged d80. The key will be the inner ring gear diameter so the gear set would be properly aligned with a d80 ring gear.
05-07-2007, 09:19 AM
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Just a comment fyi. I think that a d80 pl would have the same internals, clutch stack and parts, as the d70 pl pictured. I would bet that the rebuild kit has the same part number. I could allways be wrong but I wonder if the ring gear diameter is the only difference between the two. I am sure that that applies to detroit lockers and suspect it might be the same with pls as well. Does anyone know for sure? It would be nice to be able to just slot the ring gear holes and use a d70 pl in my traction challanged d80. The key will be the inner ring gear diameter so the gear set would be properly aligned with a d80 ring gear.
05-07-2007, 09:48 AM
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Yeah....i just did my Dana 80 in my truck (Hence why RowJ asked me for my help and i was visiting Texas for the weekend) It was almost the same except for the clutch part. The clutches were 100% different.
My 80 didnt have all the clutches stacked, so i restacked them. Other than heavy throttle in corners, it doesnt feel any differant.
BUT RowJ's were all stacked...felt bad about pulling it until i saw the ware one of the plates shown above. Then it was more justified!
If we had air from the start, it would have gone real fast....but we did about 80% with hand tools (Yeah...those case bolts and axle bolts are TIGHT!) until my bud came back from the vet tending to a dog emergency.
After we got done…that chatter from the new plates was VERY disconcerting. I would have to assume normal….but man…a truck is not supposed to make noise like that from the rear end! Haha…. I felt WAY better when RowJ called me and said that it was getting better the more he drove…..
All in all…..fun…..glad I got to help with it….
My 80 didnt have all the clutches stacked, so i restacked them. Other than heavy throttle in corners, it doesnt feel any differant.
BUT RowJ's were all stacked...felt bad about pulling it until i saw the ware one of the plates shown above. Then it was more justified!
If we had air from the start, it would have gone real fast....but we did about 80% with hand tools (Yeah...those case bolts and axle bolts are TIGHT!) until my bud came back from the vet tending to a dog emergency.
After we got done…that chatter from the new plates was VERY disconcerting. I would have to assume normal….but man…a truck is not supposed to make noise like that from the rear end! Haha…. I felt WAY better when RowJ called me and said that it was getting better the more he drove…..
All in all…..fun…..glad I got to help with it….
