Rear End Lock

[George Maz]

4.10 mod wasn't done recently. The transmission and shifter felt real good. Engine was strong, cams & Corsa sound mean. Any recent work (a ton of it) was unrelated to the transmission, to my knowledge.
Dempsey will have more info when he opens it up.

So, I should look for a replacement transmission with Bill's spline modification?
Or, send him my core for exchange or rebuild?

[A26B]

My transmission (94) seized & locked the complete driveline. Rollback wrecker spotted it close to my lift where I could put a jack under the 3rd member, winched it up to the lift & oiled the rear tires to slide the rest of the way on. Locked up solid just cruising around town.
Sent it to Bill Boudreau for the full ZF Doc treatment.

[tf95ZR1]

Wow, 2006! Deja Vu all over again.
I agree with Paul & Jerry.
My BB trans has performed BEAUTIFULLY ever since.
Smooth, positive shifting, no noise. And like other times
I have broken, I use it as an excuse to upgrade: BB short shifter
is the BOMB! (my kids tell me that's a good thing.)
From what I remember: broke down in the desert. Buddy
took me into town and I rented a U-Haul and trailer.
Backed car up onto trailer and took her home. I removed
the half shafts and pushed my car into garage. Dropped trans
(MUCH heavier than I expected). REALLY fun lining up
trans/splines/shaft lying on your back under car up on jack stands.
I now have a Kwiklift but 2 - 4 post lift with trans jack is best.

PS: Or have somebody like Dempsey or Bill nearby

[GOLDCYLON]

Originally Posted by George Maz

4.10 mod wasn't done recently. The transmission and shifter felt real good. Engine was strong, cams & Corsa sound mean. Any recent work (a ton of it) was unrelated to the transmission, to my knowledge.
Dempsey will have more info when he opens it up.

So, I should look for a replacement transmission with Bill's spline modification?
Or, send him my core for exchange or rebuild?

As suggested earlier I once again suggest you call Bill to discuss the options. It is really is the ONLY smart way forward if you plan on keeping the car. If you haven't done so already I also highly suggest the beam plates upgrade while you are there as well.

[Dynomite]

Jumped from 2006 to 2016. So.....what are the odds and what are contributing factors?

Bill says If there is an oil level and/or oil condition issue, this is the area in the transmission which is prone to seizure.

What are the Oil Level and Oil Condition ISSUES?

Oil Level is obvious but am I to assume some oil levels are significantly below the top fill port?

And.....am I to assume if you have fresh TWS 10W-60 Castrol you are in good condition and have significantly reduced the chance of this Transmission Lock Up to happen?

I have Bill's C4 Beam Plates on ALL ZR-1s

[oricale]

Hey all!, we are in the process of going through George's car, the transmission is out, the trans oil has been checked, levels were correct and albeit full of bits of transmission, it was clean..pilot bearing is shredded and partially laying in the snout (location of engagement of trans to crank). We are pulling the clutch pack for inspection as well as replacing u-joints on the drive shaft, the event was pretty violent.---more to follow----

As far as modding for 4/10 gears.....I am aware of at least 5 guys on the site that utilize 4/10 gears with no mods and drive 1000's of miles with no issues.

However, if there is a mod that will guarantee a life free from a trans eating itself due to this issue,.. and its proven. I'm all about it.

First drive breakdown blues are a downer

[George Maz]

Beam plates on both cars already...huge difference in driveline deflection (rear-end kickout), and rising shifter when a rear top plate was lost recently on #1587. Bill made one up for me.

As per your suggestion, I left a message for Bill today. I'm of the opinion to fix it right, fix it once...although I would like to hear everyone's experience. I'm told there are a handful 4.10 geared cars, driven long distances that haven't had this transmission failure occur.

Once the car abruptly decelerated itself from highway speed cruising in 6th gear, all I had for movement was a crunchy sounding reverse gear. Any forward gears would stall the engine. Then the trans got stuck in reverse, regardless of any shifter position. The clutch has to be depressed to push the car around, so I'm not completely locked up.

[Dynomite]

Originally Posted by A26B

My transmission (94) seized & locked the complete driveline. Locked up solid just cruising around town.

OK......What caused this or are we driving ZR-1s that can for no particular reason all of a sudden lock up at any time (that would be hell in traffic for sure).

Or are we driving AT RISK ZR-1s that in their history have run for a long while low on oil or oil not changed at any particular interval.

What would prevent this and how often does this occur? what are the statistics?

Or....can we put this issue in the same category as Timing Chain Catastrophic failures (I know of only two) which are extremely rare and equally unpredictable.

[A26B]

Bill Boudreau would be the best one to obtain failure statistics and cause. I recall several failures of transmission seizures over the last 14 years, but it would be a stretch to say it's anything more than than an uncommon occurrence.

Circumstances of my particular failure;
Model: 1994
Mileage: appx 60,000 miles
Lube: original fill replaced with Redline. Original oil was full & clean. Failure occured within 2,000 miles of Redline. I make no claim that Redline was the cause.
Impending failure warning: Slow roll to stop, clutch depressed, no brake, could feel slight abnormal decel & stop with brake. Knew something was wrong & started home. made it about 4 miles.
Conditions: Cruising in town, speed 0~45mph.
Failure: left stop sign, rolling resistance significant, clutch no effect. Seized completely.

[A26B]

Originally Posted by Dynomite

.......... Timing Chain Catastrophic failures (I know of only two) which are extremely rare and equally unpredictable[/B][/COLOR].

I am aware of 1 case of timing chain failure that was directly attributed to cam cover chain guide that came loose after powdercoating. Guide (facing removed) was left in place during powdercoating. Loctite may have been affected by heat.