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MG TD TF 1500 - Cam shaft run against chain cover - why? - 2nd pic

the other side

W_Mueller

Just for your info, you can post more than one photo in a thread (but only one photo per post), I think you can post at least three posts with a photo in each one after the other.
HTH.
Nigel Atkins

Thank you Nigel for that hint!
W_Mueller

Could the circlip on the back end of the cam have been omitted? That's what prevents the cam from walking forward.

Are the variouos parts at the front of the cam, against the timing gear, installed correctly? The washer, oil thrower and tab? Could they be protruding forward too much?

Tom Lange
MGT Repair
t lange

The cipclip prevents the camshaft from moving rearward during timing gear installation but doesn't control forward movement, nor movement in either direction once the thrust plate is installed. The thrust plate is what prevents the camshaft from moving either direction. It seems like you'd have to have a LOT of play at the thrust plate to allow the timing gear bolt to hit the cover or the camshaft to hit the rear plug. Have you checked the play? Is the timing gear bolt the correct type? Are there too many washers stacked up behind it? Is the home-made plug in the rear protruding farther inward than a correct dished plug?
Steve Simmons

check that the woodruff key on the cam chain wheel had not rotated when you fitted the timing chain.,
If it rotates it jams and leaves a massive clearance on the thrust plate allowing the cam to shunt about.
I did a friends car earlier in the year and we had the chainwheel off 3 or 4 times before it went in correctly.
Ray TF 2884
Ray Lee

Thanks for the clarification and correction to my post, Steve. Accuracy is important!

Tom Lange
MGT Repair
t lange

I should have said the mark on the timing cover is the bolt head too far forward because of the key fouling. I would also check if the circlip has been pushed out of it's slot and is riding the core or is in the sump.
Ray TF 2884
Ray Lee

Thanks to all!


I'm sorry but it is too late for checking all the mentioned things because the cam shaft was dismantled while I was absent. It is also possibel that the touch happened in the past during mounting the cam shaft and the sprocket.

The thrust plate is not worn. The home-made plug in the rear protrudes farther inward than a correct dished plug. But I didn't found a circlip and no oil thrower in the box with the removed parts. That does not explain the scratches on the chain cover. May be the bolt is wrong. It is a modern M12x 1,5 bolt. Are the old whitworth heads shorter than the ISO? A new bolt from MOsS or B&G will enter my wishlist. If the head ist critical I guess they will deliver the right one.

I'll tell the machine shop to pay high attention to this circumstances.
W_Mueller

The head of the cam gear bolt is about half the height of a standard bolt, and yes, you should use it. The proper order is the gear, the oil thrower (concave side facing the gear), the washer, the locking tab (which has a pin that locates all three through holes), and the thin-head bolt.

I bet the new bolt stops the rubbing.

Tom Lange
MGT Repair
t lange

Tom - the puzzle has a solution!
W_Mueller

Yes the original bolt has a very flat/short head. With the home made rear plug, it looks like the rebuilder used whatever they had laying around. I read somewhere that the circlip was to keep the cam from being bumped backwards and accidentally knocking the rear core plug loose when installing the gear, etc. George
George Butz III

I got the spare from Brown & Gammons. It is M12 x 25mm.

Regarding to DIN 933 or ISO 4017 the head should be 8mm or 7,5mm thick. The bolt from B&G is 8mm. So that bolt is not special. I guess it is a blank and we have to cut the head.
W_Mueller

Had this happen on my rebuild. the cupped deal that has the tab was installed wrong. I did it. that little tab has to be in the right spot. I tightend it up and it came loose as it was not right and all of a sudden the cam is pushing against the front cover. took it apart, put in new cam bearings again and did it right the next time. The Moss engine diagram list this as part 64 the tab was not quite in the hole when I screwed up.
TRM Maine

Thanks TRM

For all in U.S.A.

Abingdon Spares pictures the right bolt with a flat head in the online catalogue
W_Mueller

And now you'll be one of the guys who caution newbies against making this mistake based on personal experience. Learning something new is always a good thing! Mayne not the way we have to learn, but still. ;)
Steve Simmons

I think also the tab pin going through the three holes should enter the key slot. Could be wrong but I just did it on my rebuild. Marvin,ct
M.D. STUART

This thread was discussed between 22/11/2018 and 06/01/2019

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