Does this differential look normal?
Thread Starter
Racer
Joined: Jun 2005
Posts: 298
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From: Franklin MA
Does this differential look normal?
It looks like something has grind the casting mark off? See the closeup picture below.
The teeth mark (not the actual teeth) on the picture below are not smooth. It's more like a ripple. The picture couldn't show it well.
Also, the fluid that came out of the differential smelt burnt. I din't pay attention to see if there is any metal in the fluid.
Thanks for the help.
Burning Brakes
Joined: Feb 2001
Posts: 929
Likes: 5
From: Marietta GA
Let me preface my comments by saying I am not a differential expert. I recently had my differential rebuilt and one thing I can tell you about yours is that the pinion gear is hitting the posi case. Not a good thing. I cannot speak to the teeth marks on the ring gear, but that doesn't quite look right either.
Back to the pinion, it is possible that the pinion contact has caused the posi to crack. I think you are definitely in for a rebuild, but hopefully a differential expert will chime in. I had my diff rebuilt by Gary Ramadei (GTR1999), and he did a great jiob.
Back to the pinion, it is possible that the pinion contact has caused the posi to crack. I think you are definitely in for a rebuild, but hopefully a differential expert will chime in. I had my diff rebuilt by Gary Ramadei (GTR1999), and he did a great jiob.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
A little hard to tell from the pictures, but the machining on the carrier housing is normal. The stains that show the pinion teeth shadows are interesting. Looks like the fluid has been hot or something unusual. I think that I would check the mesh pattern. If you were not hearing any unusual noises and the pattern checks good, I would change the clutches and bearings while I had it out. Everything should be OK then.
Tech Contributor
Joined: Aug 1999
Posts: 15,135
Likes: 3,939
From: Connecticut, USA
As Mike said, the pinion hit the case and that pattern doesn't look too good. Use some brake cleaner and wash it down good for a better look. I've had some that looked like they were powder coated inside from baked on oil.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Are you saying that the pinion was loose enough to hit the posi case here. I dont really see that. But like I said it is hard to tell in the pictures. The area of the picture that is circled has to be a shadow. That area has a good radius and is not level. That pinion didnt hit that whole area. There is one place it looks like it might have hit on a high spot in one of the other pictures.
Burning Brakes
Joined: Feb 2001
Posts: 929
Likes: 5
From: Marietta GA
Wombvette, look at the first picture. The front face of the pinion gear is shiny and has marks on it. If you look carefully at the case, you can see the marks that the pinion left on the case, this pattern is circled on the last picture. It doesn't necessarily mean the case is cracked but it should be checked IMHO.
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Tech Contributor
Joined: Aug 1999
Posts: 15,135
Likes: 3,939
From: Connecticut, USA
It hit the case but not as bad as the one Dan shows. That looks to be a C2 diff btw.
The brake cleaner will remove the baked on oil and show up any cracks it may have. If the case isn't too bad and the application is a mild street car then it can be radius polised and reused- as long as it's not cracked.
I would, without question,take it apart and go through it.
The brake cleaner will remove the baked on oil and show up any cracks it may have. If the case isn't too bad and the application is a mild street car then it can be radius polised and reused- as long as it's not cracked.
I would, without question,take it apart and go through it.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Wombvette, look at the first picture. The front face of the pinion gear is shiny and has marks on it. If you look carefully at the case, you can see the marks that the pinion left on the case, this pattern is circled on the last picture. It doesn't necessarily mean the case is cracked but it should be checked IMHO.
Tech Contributor
Joined: Aug 1999
Posts: 15,135
Likes: 3,939
From: Connecticut, USA
The spot outlined in the black circle is not from a pinion hit but rather a machine turning. The spaced tooth edge marks are from the pinion. Regardless the best approach would be a careful cleaning and inspection. If there are cracks there it will fail.
Thread Starter
Racer
Joined: Jun 2005
Posts: 298
Likes: 0
From: Franklin MA
A little hard to tell from the pictures, but the machining on the carrier housing is normal. The stains that show the pinion teeth shadows are interesting. Looks like the fluid has been hot or something unusual. I think that I would check the mesh pattern. If you were not hearing any unusual noises and the pattern checks good, I would change the clutches and bearings while I had it out. Everything should be OK then.
Are you saying that the pinion was loose enough to hit the posi case here. I dont really see that. But like I said it is hard to tell in the pictures. The area of the picture that is circled has to be a shadow. That area has a good radius and is not level. That pinion didnt hit that whole area. There is one place it looks like it might have hit on a high spot in one of the other pictures.
It hit the case but not as bad as the one Dan shows. That looks to be a C2 diff btw.
The brake cleaner will remove the baked on oil and show up any cracks it may have. If the case isn't too bad and the application is a mild street car then it can be radius polised and reused- as long as it's not cracked.
I would, without question,take it apart and go through it.
The brake cleaner will remove the baked on oil and show up any cracks it may have. If the case isn't too bad and the application is a mild street car then it can be radius polised and reused- as long as it's not cracked.
I would, without question,take it apart and go through it.
My car is not a number matching car and I'm not very knowledgeable at what to look for (other than it doesn't look normal). Would it be wise just to get a new rear end? I've heard a lot people here mentioning Tom's Differentials. Thanks for all the help.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
"The machining on the carrier housing is normal." Are you talking about the marking on picture 3? I think the fluid must've been hot because it smelt burnt. What is the mesh pattern that you are refering to.
The teeth mark on the fourth picture is definitely not a shadow. It looked more like burn mark.
Mine look very similar to the one in Dan's picture. Like you said, it's just not as bad but I can see something grinding away the metal housing.
What do you mean by "the black circle is not from a pinion hit but rather a machine turning"?
My car is not a number matching car and I'm not very knowledgeable at what to look for (other than it doesn't look normal). Would it be wise just to get a new rear end? I've heard a lot people here mentioning Tom's Differentials. Thanks for all the help.
The teeth mark on the fourth picture is definitely not a shadow. It looked more like burn mark.
Mine look very similar to the one in Dan's picture. Like you said, it's just not as bad but I can see something grinding away the metal housing.
What do you mean by "the black circle is not from a pinion hit but rather a machine turning"?
My car is not a number matching car and I'm not very knowledgeable at what to look for (other than it doesn't look normal). Would it be wise just to get a new rear end? I've heard a lot people here mentioning Tom's Differentials. Thanks for all the help.
When I said it looks like a shadow, I didnt mean a light shadow, but deposits left by cooked oil. The teeth pattern seen in the circle is deposits left by the oil creating a shadow effect.
When I said "mesh pattern" I mean check the pattern on the gear. It is set up to run in a specific way. That pattern is checked with lead paint to see if the gear is set up properly.
The machining on the carrier marked by black lines in picture #3 is normal. Done in the machining process of the carrier.
Tech Contributor
Joined: Aug 1999
Posts: 15,135
Likes: 3,939
From: Connecticut, USA
The machining on the carrier marked by black lines in picture #3 is normal. Done in the machining process of the carrier.[/QUOTE]
I agree with this as well.
No, you're better off rebuilding yours then you know what goes into it and how it was done. It can be built several ways so I would do a search to see.
I agree with this as well.
No, you're better off rebuilding yours then you know what goes into it and how it was done. It can be built several ways so I would do a search to see.
Safety Car
Joined: Oct 2006
Posts: 3,930
Likes: 15
From: Calgary Alberta
I agree. It will take longer to rebuild and probably will cost a little more than if you sent it out to be done (you need a 0-30 in/lb torque wrench, a $100 press and a cheap engine stand), but you can rebuild it by yourself better than anyone out there. On the plus side, if it ever breaks down again, you can rebuild it yourself!
Thread Starter
Racer
Joined: Jun 2005
Posts: 298
Likes: 0
From: Franklin MA
I agree. It will take longer to rebuild and probably will cost a little more than if you sent it out to be done (you need a 0-30 in/lb torque wrench, a $100 press and a cheap engine stand), but you can rebuild it by yourself better than anyone out there. On the plus side, if it ever breaks down again, you can rebuild it yourself!
Gary, when you said clean it with brake cleaner, did you mean taking the differential apart and clean it or just clean it the way it is right now?
Tech Contributor
Joined: Aug 1999
Posts: 15,135
Likes: 3,939
From: Connecticut, USA
Don't take it apart. Use the cleaner on it and check it or drive to New Haven over the weekend and I'll look at it for you. If you remove the case then you'll get into shim issues unless someone rebuilt it before and used the steel shims.
Thread Starter
Racer
Joined: Jun 2005
Posts: 298
Likes: 0
From: Franklin MA