Hi Blizzy
good luck on your transmission issue

I also have a trans question for you since you have had the rear section off while doing the shifter extension (which I will proceed with shortly as I was able to score the 2 parts needed)


have you upgraded the Bearing Cover Plate. I was thinking of getting the part from Marlin
http://www.marlincrawler.com/htm/tra...rans_parts.htm
since the rear section was coming off anyways

 

Thanks Blizzy, you actually unknowingly just helped me to identify a Supra auto TT LSD that I wanted to buy.

Thanks,
Ryan

 

Mark,
I seen you posted on another thread so I know you are out there. Hows the car coming? Big plans for summer break? I hope all is well.

 

It's alive.

It has been a long journey of virtual nothingness as far as the Lexus has been concerned. If you recall, last July 4th, I had the issue with the clutch disc. It is nearing July 4th this year, and I finally got to fixing it. A buddy of mine in town gave me a big boost in getting the job done by calling me back-to-back nights on Monday and Tuesday to force me to get under the car to both diagnose and fix the issue.

It was clear that my slippage issue was a result of either the pressure plate not being allowed to relax because of some obstruction or a clearance issue between the pp/clutch/flywheel.

To figure it out...

I made a line in the grease on the input shaft with a putty knife to mark the position of the clutch hub in relation to it. This would be a basis of measure. If pulling the slave cylinder did not allow the pressure plate to relax any, then either the clutch disc was seized to the input shaft or the clearances on the friction surfaces were improperly machined.

After pulling the slave, the pressure plate relaxed ~1/4". This meant that the issue was almost certainly with the slave/fork assembly and not anything else: meaning no need to pull the tranny. This was frustrating, having waited almost a year to just get down there to sort it out, and relieving, not needing to drop the transmission to fix the issue.

The difference in depth between the mark from the strained pressure plate and the relaxed pressure plate was about the depth of two galvanized washers. Reinstalling the slave cylinder with the galvanized washers offered the proper clearance for the slave to fully depress without having to put strain on the pressure plate: problem solved.

In context with what happened to my old clutch...

While some of that two washer gap was a result of the flywheel being machined for the new install (maybe 1/2 of one washer at most), most of that gap would have been there on the previous iteration with the old clutch.

While the old clutch may have had just enough to grab fully when it was brand new, I suspect that the wear and tear of the first 1k miles or so in addition to the added strain of pushing the car in the heat that July 4th led to the slippage of my clutch: although the root cause was the pressure plate not being able to fully relax and apply the pressure it was designed to apply.

I suspect this slave clearance issue I have been having was a result of the proprietary nature of my transmission install in addition to my own inexperience and inability to foresee such a possibility. Perhaps anyone else who uses the TTC Adpater Plate a la carte for an R154 install should be adding four galvanized washers to their build list.

I am thrilled that the combination of -perhaps- a marginally thinner clutch disc from a new manufacturer with a certainly -albeit slightly- thinner flywheel from machining left me with a new clutch disc that was unable to engage at all. Were this new disc able to engage, I might have burned it out within 500 miles and had another reinstall to perform as a result of this slave shimming gremlin that was eluding me.

Having said all that...

The car drives great.

The engagement is not bad at all. A hybrid ceramic-metallic six puck design, the feel is only shades harsher than the full rim kevlar disc I had in there before. Expecting to have to "invest in a better dental plan" as some have suggested in the past with clutch discs of sch a persuasion, I am very satisfied with the feel of it all. I was nowhere near "stalling out when I pulled out of the driveway from the harsh engagement" like some have suggested. For that matter, I have heard no chatter without having to adopt any sort of a fancy technique when taking off.

Having driven a 93hp car for the last 12 months, keeping the car under 3k for the next 300 miles to break in the clutch disc will be relatively easy. I am so used to pulling away from stop lights slowly that another handful of hours of such driving will be nothing out of the ordinary. Once I am able to floor it to the redline, all bets are off.

Thanks to everyone who has remained interested in my car throughout this dry spell. Assuming a couple weeks go by and I show no issues with the transmission as it is set up now, I can close the book on that swap and look the exhaust manifolds squarely in the face.

 

Finally he lives!! I think some of us thought you died or something, glad to see you're back in action!!