RHanselman
08-27-2005, 02:40 AM
ZF diagnosed as a Seizure
Follow-on story of my trans popping out of first gear.
My boy and I took the Z down to Bill B’s place in Phoenix on Thursday this week. Bill drove the car and confirmed that there was indeed a major problem with the unit. We removed the trans so Bill could diagnose the problem and see weather he could rebuild it or if I needed to buy a new trans.
Bill guided my son and I threw the removal process. We had the trans out in about an hour (or so) and placed it on Bill’s work bench where he started dissecting it right before our eyes. Bills knowledge and ingenuity are impressive. He has had tools made or has made tools that make his task much more easy to handle. In no time he had the trans case split and was pulling out stacks of gears.
The trans had major signs of overheating in the reverse gear area. The case magnet was full of metal shavings and your really couldn’t tell it’s real shape.
Bill removed the third gear and it was in perfect condition. However, it was the only gear he was able to remove on that stack. First gear had welded itself to the shaft and no matter how much pressure he applied on his press he couldn’t get it to budge.
That was all she wrote… I headed down to the local Chevy dealer and picked up the new trans for $1100 flat. Not a bad deal that Bill had setup for me.
We took it back to Bill’s house where we left it with him to do his magic. Over the next week he will balance and blue print the trans, open up all the oil passages, and put the guts back into my original numbers matching case. All for $600. He will put it back in the car for $225 and make sure all of the drive train is aligned back to specifications. Bill will then buy back all the good parts from my old transmission and what ever parts are left from the new one.
He is also checking out the clutch and will put in a new pilot bearing because of some overheating signs on the end of the trans shaft.
As for the cause on a 7500 mile trans…
Well we are guessing but it looks like oil starvation of the reverse gear. We think it got so hot that it welded itself and the first gear to the shaft. This happened while my boy was bring the car to me in Vegas. He was on the highway in 6th gear going 78 MPH. The car decelerated suddenly like putting on the brakes but not locking the tires. He pulled to the side of the road, turned off the car and let it sit for a few minutes. Luckily no one was behind him. He restarted the car and it worked fine. I met him an hour later but he failed to mention his problem. Would have like to know that before I did some high speed runs coming into NV. Would have not been good to lock the trans up at XXX numbers. The trans was louder than normal and was getting progressively louder as I approached Las Vegas.
We don’t know if the trans was low on oil (forgot to measure the fluid or check the level before I drained it at Bills) I know it was full last year and 500 miles ago when Corey H and I put the 4:10s in. On inspection of the reverse gear, the oil passages seemed to be really undersized. Bill surmises that the combo of 4:10s and the higher driveline speeds in sixth gear starved the reverse gear causing the seizure. Or I could have been low on oil…
Either way, no one was hurt when it seized and I get a new trans that’s balanced and blue printed for less than $2000.
Bill also said that I might have a clutch problem or a lazy foot. He will check out the clutch and I’ll start working on my technique.
Cheers,
Ron Hanselman
Follow-on story of my trans popping out of first gear.
My boy and I took the Z down to Bill B’s place in Phoenix on Thursday this week. Bill drove the car and confirmed that there was indeed a major problem with the unit. We removed the trans so Bill could diagnose the problem and see weather he could rebuild it or if I needed to buy a new trans.
Bill guided my son and I threw the removal process. We had the trans out in about an hour (or so) and placed it on Bill’s work bench where he started dissecting it right before our eyes. Bills knowledge and ingenuity are impressive. He has had tools made or has made tools that make his task much more easy to handle. In no time he had the trans case split and was pulling out stacks of gears.
The trans had major signs of overheating in the reverse gear area. The case magnet was full of metal shavings and your really couldn’t tell it’s real shape.
Bill removed the third gear and it was in perfect condition. However, it was the only gear he was able to remove on that stack. First gear had welded itself to the shaft and no matter how much pressure he applied on his press he couldn’t get it to budge.
That was all she wrote… I headed down to the local Chevy dealer and picked up the new trans for $1100 flat. Not a bad deal that Bill had setup for me.
We took it back to Bill’s house where we left it with him to do his magic. Over the next week he will balance and blue print the trans, open up all the oil passages, and put the guts back into my original numbers matching case. All for $600. He will put it back in the car for $225 and make sure all of the drive train is aligned back to specifications. Bill will then buy back all the good parts from my old transmission and what ever parts are left from the new one.
He is also checking out the clutch and will put in a new pilot bearing because of some overheating signs on the end of the trans shaft.
As for the cause on a 7500 mile trans…
Well we are guessing but it looks like oil starvation of the reverse gear. We think it got so hot that it welded itself and the first gear to the shaft. This happened while my boy was bring the car to me in Vegas. He was on the highway in 6th gear going 78 MPH. The car decelerated suddenly like putting on the brakes but not locking the tires. He pulled to the side of the road, turned off the car and let it sit for a few minutes. Luckily no one was behind him. He restarted the car and it worked fine. I met him an hour later but he failed to mention his problem. Would have like to know that before I did some high speed runs coming into NV. Would have not been good to lock the trans up at XXX numbers. The trans was louder than normal and was getting progressively louder as I approached Las Vegas.
We don’t know if the trans was low on oil (forgot to measure the fluid or check the level before I drained it at Bills) I know it was full last year and 500 miles ago when Corey H and I put the 4:10s in. On inspection of the reverse gear, the oil passages seemed to be really undersized. Bill surmises that the combo of 4:10s and the higher driveline speeds in sixth gear starved the reverse gear causing the seizure. Or I could have been low on oil…
Either way, no one was hurt when it seized and I get a new trans that’s balanced and blue printed for less than $2000.
Bill also said that I might have a clutch problem or a lazy foot. He will check out the clutch and I’ll start working on my technique.
Cheers,
Ron Hanselman