TDR,
I think a lot of you have figured it out that I work for a clutch company and the CTD is my truck of choice.
This tale is not brand specific, in fact the clutch was an innocent bystander, but this story was too painful not to pass on to the membership.
G56, unable to shift.
Pilot bearing failed, input shaft damaged at pilot nose, clutch disc splines showing a wiping pattern with side burrs in the tooth flanks. The owner had to park the truck as they could no longer shift it, disassembly found the above list of visible damage.
I had a long discussion with the neighbor that was fixing the truck for the owner, they were good friends to say the least. As we went over the list and searching for the RED X that indicated ground zero for the the symptoms started to point in one direction, this clutch system was killed due to concentric misalignment or a combination of concentric misalignment and angular misalignment of the input shaft to the crankshaft. I explained to the caller what the problem looks like by using your index fingers and touching them tip to tip, perfectly straight, now drop one finger down by 1/16" or so and give it a couple of degrees of downward angle, now put the pilot bearing at the tip to tip and the clutch disc, pressure plate and flywheel in the middle, see how this would tear up the pilot and the disc as it tries to be a flexible coupling and rag joint to this misalignment.
What controls the input shaft to crankshaft alignment?
The two dowel sleeves on either side of the engine adaptor and they slide into precision holes in the transmission. The bolt holes are a clearance fit and do not control alignment, they only clamp the parts together.
The caller then went out to the truck, got under it and said you mean these right here?
He stated that the dowel sleeves had been cut off flush at the engine adaptor to trans face with a saw or grinder. He could see the tooth marks in the aluminum.
The installation that they paid big money for was no easy way to say it a butcher job. And I don't mean to insult the fine meat cutters that read this, I just don't have another word for it.
The repair will require removal of the stub ends of the sleeves, cleaning up the holes, but the BIG investment is getting the damaged input shaft replaced and any damage to the input shaft bearing and related internals.
One of the biggest challenges to any successful repair for clutches or for that matter any repair is ATTENTION TO DETAIL, this was not lack of attention to detail it was a willful act that is now costing the owner big unnecessary additional repairs.
When I do an installation, I clean the sleeves if necessary with a Scotch Brite or similar and the mating holes and then apply a light coat of grease to make them slide freely and help prevent corrosion.
The one thing that I went home feeling good about was that the over 45 minutes that we spent walking through the entire situation rather than giving the caller a quick answer was I'm very confident that we found the RED X.
I think a lot of you have figured it out that I work for a clutch company and the CTD is my truck of choice.
This tale is not brand specific, in fact the clutch was an innocent bystander, but this story was too painful not to pass on to the membership.
G56, unable to shift.
Pilot bearing failed, input shaft damaged at pilot nose, clutch disc splines showing a wiping pattern with side burrs in the tooth flanks. The owner had to park the truck as they could no longer shift it, disassembly found the above list of visible damage.
I had a long discussion with the neighbor that was fixing the truck for the owner, they were good friends to say the least. As we went over the list and searching for the RED X that indicated ground zero for the the symptoms started to point in one direction, this clutch system was killed due to concentric misalignment or a combination of concentric misalignment and angular misalignment of the input shaft to the crankshaft. I explained to the caller what the problem looks like by using your index fingers and touching them tip to tip, perfectly straight, now drop one finger down by 1/16" or so and give it a couple of degrees of downward angle, now put the pilot bearing at the tip to tip and the clutch disc, pressure plate and flywheel in the middle, see how this would tear up the pilot and the disc as it tries to be a flexible coupling and rag joint to this misalignment.
What controls the input shaft to crankshaft alignment?
The two dowel sleeves on either side of the engine adaptor and they slide into precision holes in the transmission. The bolt holes are a clearance fit and do not control alignment, they only clamp the parts together.
The caller then went out to the truck, got under it and said you mean these right here?
He stated that the dowel sleeves had been cut off flush at the engine adaptor to trans face with a saw or grinder. He could see the tooth marks in the aluminum.
The installation that they paid big money for was no easy way to say it a butcher job. And I don't mean to insult the fine meat cutters that read this, I just don't have another word for it.
The repair will require removal of the stub ends of the sleeves, cleaning up the holes, but the BIG investment is getting the damaged input shaft replaced and any damage to the input shaft bearing and related internals.
One of the biggest challenges to any successful repair for clutches or for that matter any repair is ATTENTION TO DETAIL, this was not lack of attention to detail it was a willful act that is now costing the owner big unnecessary additional repairs.
When I do an installation, I clean the sleeves if necessary with a Scotch Brite or similar and the mating holes and then apply a light coat of grease to make them slide freely and help prevent corrosion.
The one thing that I went home feeling good about was that the over 45 minutes that we spent walking through the entire situation rather than giving the caller a quick answer was I'm very confident that we found the RED X.