Holes in bellhousing

[77highlux]

Hey all,
Had something super interesting happen today. I blew three half dollar sized holes through my bellhousing today. The truck is a 77 Toyota pickup with 4x4 Toyota axles, soft locker in the back on 37s. I was doing donuts and let off to stop and my truck shut off and made a small clanking noise. I'm running a mr2 turbo ceramic clutch, the 1uz hasn't loved it but it worked well all the same. Through the holes I can see some deep gashes in the side of the pressure plate. Clutch only has about 1k miles on it. Anyone have a good guess as to what went? The truck is in another area but I'll post again when I pull her apart and see what the culprit was.

 

[Zuffen]

What flywheel are you running?

I suspect the flywheel isn't running true and it's caused the clutch plate to shed the friction material and has spat it out and through the bell.

 

[gloverman]

Looks like there's a little man inside your bell with a big hammer.

I've seen one bellhousing destroyed before but not nearly as best as that. It was pretty much cut in half due to a clutch being adjusted incorrectly. Basically it was adjusted so the clutch was never released fully. No free play in the system causing a reducing the clamp on pressure plate and resulting in slippage. This slippage produces heat and the pressure plate friction surface overheated and shatters. Hence a bellhousing which was pretty much cut in two.


I've seen incorrectly adjusted clutches hundreds of times now with conversions.

Another issue can be the surface and friction material used. Many flywheel and covers aren't designed to handle ceramics or brass.

I use a chrome moly flywheel for all my conversions and if running a brass plate for high horsepower or off-road with mud I use a chrome moly pressure plate too. That handles the increased heat produced.


While I've used heaps of MR2 flywheel in the beginning I now remove everyone that I see. I was never happy with them.

I'm picking either cover bolts or more likely pieces of friction plate or pressure plate. It will be interesting to see.

 

[77highlux]

Gloverman, thanks for the detailed response. I went through a swap kit company out of CA and was less than impressed with the amount of slippage I was experiencing. I'm sure you are onto something with the clutch being misadjusted. It likes to hop when taking off in first and when I stomped on it in certain high stress applications the engine screams but the tires never seemed to get the power.

The flywheel is steel and is sourced from the same company as the kit and the throw out is a chevy based hydraulic type. They also suggest running a 4runner clutch with the kit. Another guy I know is having different issues but issues all the same. I suppose the manufacturers "professional" tuning is a little out. I guess measuring again and shimming is my only option for adjustment?

Are there any great kits you would suggest as a replacement that would work well on a w56 tranny? Going to tear down this coming weekend (hopefully) and will post some pics of what I find.

 

[gloverman]

I supply parts over here in NZ. I have a few clutch options. I've considered setting up a distributor in the USA but I'm pretty busy over here as it is. I have developed and internal bearing too. Looked at the LS ones but I found they were too long for my clutch stack height.

Off-road with mud and big tyres I use my motorsport unit. Moly on both clamp surfaces and brass plate. I don't like brass for road use but it's what handles power, mud and big wheels. Sometimes there's a slight shudder on first take off but it's designed for race use.

When I'm at my laptop I'll flick some links to my parts for a reference. Today I'm sending parts to oz.

 

[77highlux]

I've been looking at clutches this week and am leaning towards a stage 4 XTD 6 puck disc without pressure springs or the 1600lb marlin crawler clutch kit. I've heard/read great things about the Marlin kit

 

[gloverman]

This is the setup I use, sell and recommend

http://www.trademe.co.nz/Browse/Listing.aspx?id=1357764990

Cheers

 

[77highlux]

Thanks for the link Gloverman. I took the tranny off this weekend and discovered that one of my adapter plate bolts backed itself off somehow and started ricocheting around the bell poking holes as it caught the edge of the PP. Clutch actually looked fine other than that, maybe some premature wear from hard usage and slippage. I'm taking your advice and have sourced a 2500lb clutch kit here in the states that should fix that. I'm going to tack the remaining adapter plate bolts lightly in place with my TIG as I'm not trusting Loctite for the job in there any longer. Should last for a good long while now. I'll post pics when I have a chance