Hey guys,



I'm in need of a rebuild for my '87 TII. I have a spare engine that I'm working on, but the car it was pulled from took a healthy hit and the center housing is cracked right above the motor mount.



I have another engine (160k or so, destroyed front rotor and housing) whose center housing I was thinking about using for the rebuild (to replace the cracked one). The only problem is that the machinist I took it to, to have it resurfaced, said he'd have to take off a minimum of .005" on each side.



My question is: what is the maximum amount of material that can be machined off of these? Will I still be good is I have this one machined? If not, does anyone have a good used one that they'd be willing to sell?



Thanks,

Dustin

 

I don't see any particular problem with that- he's not going to go through to the water jacket with 5 thou each side!



The only drama comes when you lap the plates so much that the coolant seal grooves become too shallow to retain the seals properly.

 

BUY NEW ONES! You get what you pay for, you will be rebuilding it sooner if you used ones.

 

Is e-shaft endplay affected by this? Or, is water seal depth the only thing I need to be concerned about?



THX

 

e-shaft endplay is most definitely affected, you will probably need to reset it. It should still be easily within range.



J

 

The endplay is set by using a spacer at the front of the engine, right? I see that spacers are available in sizes ranging from 8mm to 8.08mm. .08mm is only .003”. What is the correlation between e-shaft endplay and center housing thickness? Is some of the extra “space” created by machining the faces taken up somewhere other than at the spacer?



This is my first attempt at a rebuild....only doing a partial as I have another engine that I will be building with new parts. I'd rather mess up $200 worth of new parts as opposed to all the $$ involved in parts for a full rebuild.

 

Endplay has nothing whatsoever to do with housing or plate thickness!!!!



The bearing plate through which the front stationary gear bolts go is the ONLY part that determines endplay, along with the spacer of course. Think about it, the two needle bearings get squashed between this plate with the spacer stopping them from getting crushed... doesn't matter what is to the rear of the front plate.



Buy new if you can afford it, or get them machined. But then, by the time they're machined and preferably re-nitrided, your cost starts to approach new price. Having said that, I've used many second hand plates in motors I've built and never had a problem as long as you start with a good one.

 

You're right, been too long since I had one apart.



J

 

Ok, so endplay is not affected at all by housing thickness....



I think I'll just lap the housing and call it good. If I had the $$ I'd just buy a new one......I am using this engine as a learning experience (playing with porting while it's apart). I don't want to throw a bunch of $ at it.....I'll save that for the engine that is coming out of the car (blown water seal).



Thank you for your help guys.

 

Look at this way. If yoy shave off .05mm off each housing that equals .020 total. The side seals, corner seals even oil seals will have to move that much more to make up the space. I know the toterances are pretty close for all the above, so the likelyhood of one of them failing is inscreased.



I rebuild a motor with used parts once, I was pulling it back out after 3 months. Not to much fun