Add me to the "snapped pinion gear" club......

Did get several 1.57 60' times out of it this weekend though.

Almost hit 300 passes with it before the first breakage though.

 

Ohhh no!!! I was hoping it was isolated incidents for some of us. Was it from wheel hop during burnouts? I'm hoping it happened at the line and no other damage occurred. Time and time again it probably just fatigues the metal until it just snaps clean. I don't think the carrier has room for anything larger. It tapers down where it needs to remain big as it exists the differential.

Were you able to make some decent passes with the 1.57s? I am forced to rethink my future in racing, I was hoping to have another go at it, but now I might be a little gun shy. Racing really isn't the place to have a few drinks to build courage. LOL. Good luck moving forward. Let me know If I can help here on the main land.

 

I never get wheel hop on my burn outs, it happened right as I launched. I don't think much if anything else got hurt, but there is always the possibility of driveshaft damage when that happens. My hope is its just a new ring & pinion with install kit/bearings/seals. What did the new ring & pinion cost you when yours broke? Is that all you needed? Thinking it might be time for flex discs too if I'm going to pull the driveshaft & inspect it anyway.

Didn't run good numbers either. Not sure why, but it ran 11.02-11.06 every pass and was only hitting 123mph. There is something weird going on but as it was running the same # every time I figured I'd go with it for bracket racing and figure it out tonight after that was done. Tthe weather was so cold my A/C wasn't kicking on and had lots of time in the staging lanes, so with no A/C my killer chiller wasn't doing anything and IAT's were really high. The car normally runs faster and faster as it adapts to the 109 octane, but in 20 passes later it was still at the same ET and mph, even when I got the A/C working by turning on the defroster which lowered my IAT's by about 100*! Tried to data log and my Euroflash software kept telling me "can't confirm VIN".

 

I don't think they sell the ring and pinion separate, even though you can identify the part numbers. It may turn into a long back order like any dated parts from Mercedes. I think I ended up with a re-man. diff and had the Quaife swapped. I didn't do it, I had it done at a shop. I did do the flex discs at that time. I remember being shown slight ovaling on the internal bolts of the diff, in the direction of drive from several hard launches.

Sorry to hear the low traps. It almost sounds like you were running a stock tune with the benefit of the fuel and low temps. I always run the same tune. Do you have a lower octane tune as a default with more timing? No check engine light or any codes? These cars can get so frustrating at times.

 

No CEL, haven't changed the tune in years. I'll figure it out eventually, but was planning to retire the CL from the track after today and get busy on the new build this winter to take over race duty from the Mercedes.

 

Sorry to hear about that Dr Matt.

Racing has a long and proud tradition of finding out how to faster the hard way. Thinking pragmatically, maybe you could find a good salvage 55K diff? The chances of finding another '65 unit must be slim. I guess E/S/SL/CL must be similar. I had my rear end out last month; it's not that bad.

Nick

 

Here are a few pics of what a sheared pinion gear looks like. I've had the opportunity to see one first hand. I think they are specific to the S and CL 65 since the last two digits say "65". The carriers may be the same for the CL55 and S55, but the part number leads me to believe the internals may be different.

 

Mine snapped in the exact same spot. Hopefully I can get parts quickly.

 

It's the thinnest part after the grooves are machined out. I wonder if the internals could be matched with a larger end, but it probably wouldn't fit the cast of the carrier.

 

Well it's all together & back on the road. Long time to wait to drive my CL since I snapped the pinion gear in half Labor Day weekend. Just need to get it aligned now as the right rear is toe in is actually "toe out" right now. I'll set it a little closer tomorrow as it is clearly way off. Traction seems limited, but that may be partially because last time I drove it I was on drag radials and a prepped track, not ice, lol.

 

Glad to hear it's back on the road. How did you fix it? Did you get a new pinion from the dealer?

Nick

 

No, I bought a complete used differential assembly, rear axle, and hub assembly from a wrecked S65. It seems like that would make reassembly easy, but it never goes as planned. When they pulled the axles the bearings came out with them, mine had stayed in the differential. The axle was very rusty, mainly the surface the seal rides on and the threaded end for the spindle nut was hammered to the point the nut couldn't go on. The bearing on it was full of dirt and turned very rough with a pretty crunchy feel too, so I had some extra time cleaning the axle up, fixing the spindle nut threads, removing that ruined bearing, pulling my old bearings, and combining parts to get it all together. Still saved me literally thousands of dollars compared to new parts since all of it cost about 1/2 of what just a new R&P costs.

The bad part is I am now back to an open differential. The Quaife has a surface where the axle shaft rides on it just outside where in engages the spider gears. It was all chewed up for some reason and had ruined the axle shaft. Well, once there was a problem I found out how good their "lifetime warranty" is. Ha.

I bought the Quaife from Vividracing. First call to them they said sorry, not our problem, call Quaife. Quaife said nope, call your vendor. Called Vivid back and got a different person. Totally different attitude and said sure we can handle it, just send pictures. The next response was it had been too long since I purchased it so I'd have to deal with the importer, Kleeman. Kleeman said that if it failed it was because it was either installed incorrectly or too much old clutch material from the origonal factory clutch type posi was left in the differential and that ruined it. At one point they said unless a Quaife dealer installed it it was done wrong. Both are complete BS. First of all, we all know thecame with an open differential, no clutch material to be left in there. Second of all, I didn't actually put the diff in the carrier, but took it to my buddy who owns a transmission shop. His assembly area is immaculate, he has 40 years of experience, and builds tons of transmissions and rear ends for race cars as well as street cars. More of the cars at the track I race at has his transmissions than any one else's. Trust me, he knows what he is doing. As far as reassembly, I'm sort of a keep the open wound clean before sealing it up person as my handle on here suggests, so, it was assembled properly and clean, period. The "lifetime warranty" is useless from Quaife, Vividracing, and Kleeman. Denied it based on pictures, never even wanted to see it. Seems like an improper install would have failed shortly. I had over 20,000 miles on it and almost 4 years of use.

 

Good to know about their "warranty". You guys have bad *** cars.

Is your car (RaceHorse) still on a factory diff?

 

Glad to hear you are back up and running, I would have thought with 11k miles on a used rear the thing would be in near brand new condition.

Quaife sucks for not offering to rebuild/replace or atleast look at your diff. Who's to say the LSD didn't bind up causing your pinion to snap? In the end, they should look at how few fail since most never see the torque our cars produce, instead they will lose future business for offering a meaningless warranty. That is a part of doing business that should be factored into the cost. I was lucky, mine was in good shape and able to swap to the new rear and that's a few years back. It hasn't been a problem, but who knows in due time maybe it will.

Besides the tires, I'm sure the open rear is why you notice a little loss in traction. LOL (as if you didn't know)

Thanks, assuming I'm one of the guys with a bad *** car, haha. I have a replacement diff in my car, but still stock MB replacement. I think the long term affects at the track fatigue the pinion, along with many other drive train parts. Twist, twist all in the same direction then its the straw that broke the camel's back and parts can snap. The same torque that's needed to get these heavy cars off the line, also puts a hurting on them. Limiting the torque and only offering an open rear was no mistake by Mercedes it was a financial decision to avoid additional warranty repairs. I wish there were closer landspeed events. the gears, power, weight and torque really allow the car to shine.

 

[QUOTE=RaceHorse;7322734]Glad to hear you are back up and running, I would have thought with 11k miles on a used rear the thing would be in near brand new condition.

Quaife sucks for not offering to rebuild/replace or atleast look at your diff. Who's to say the LSD didn't bind up causing your pinion to snap? In the end, they should look at how few fail since most never see the torque our cars produce, instead they will lose future business for offering a meaningless warranty. That is a part of doing business that should be factored into the cost. I was lucky, mine was in good shape and able to swap to the new rear and that's a few years back. It hasn't been a problem, but who knows in due time maybe it will.

Besides the tires, I'm sure the open rear is why you notice a little loss in traction. LOL (as if you didn't know)

Yeah, pretty disappointed in Quaife, Vividracing, and Kleeman. All three have a great reputation, but none want to do anything about a failed part with a "lifetime warranty". The diff didn't bind up, it's just the torque of these cars that snapped the pinion. I've gotten quite a few sub 1.60 second 60' times out of the car now, that's a lot of twist to move 4700#'s that quick. The professional custom trans & drive train builder who installed it says it is obvious that there wasn't enough clearance at that spot where the diff failed. All it took was a few burnouts where the posi didn't grip and it spun the right rear tire at very high speeds and it overheated that spot and led to the failure. Over the 4 years I've been running that diff there have been maybe a half dozen times it spun one tire during my burnout. If I was lined up next to a street car then I'd hear it, lift and try a burnout again. A few times I was next to an open header race car doing a burnout and couldn't hear or feel it. Last couple years I have pointed my mirrors at the rear tires when doing my burnout so I could see they were both turning. Sucks if it only heats one tire because then I'd spin off the line and if that was a bracket race, it would be over before I staged the car. Like I said, that has been very rare thanks to the Quaife. Hope yours doesn't fail as it is a $2,000 paper weight if it does.

 

Wow. Carnage is right. Glad you are back up and running Matt. I really like your car. Have missed you guys and will start a new thread about my current thinking. May be buying another MB.