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MG TD TF 1500 - Front Cam Bearing
|I feel like I could be in the verge of the rebuilder's version of Groundhog Day (the movie.)|
I just tried installing a new Moss front camshaft bearing. I made sure the journal holes were lined up and the channel for timing chain lubrication faced forward. I seated the bearing (it has a beveled side to do this) and started tapping lightly with a plastic hammer. I then used a piece of wood so it would go in uniformly. All that happened is that one end flipped over the other so it never seated flush. I took it out, cleaned it and tried again with the same result; one side flips over the other. Is there a chance the Moss bearing is too big (wider circumference than the housing) or did I do somthing so silly that I can't see it? My Groundhog worry is that I'll buy another one and promptly do the same thing again.
|Richard, you could try freezing the bush, and warming the block. Also lubricating the bush and block. Another possibility would to make a set up with heavy washers and a bit of threaded rod to appply a centred pull gradually. Tightening the rod and tapping gently may just do the trick. The problem with just hammering without a proper drift is that it is so hard to get the thing parallel with the bore, which is exactly what you are experiencing.|
|Richard; Professional cam bearing installation tools not only push against the front edge of the bearing,but also support the inner dimension during the install. Assuming the the bearing-to-block interference amount is correct,construction of an insert matching the inside diameter of your bearing from a semi-pliable material(soft wood,plastic,etc) could help a home installation. Boring a hole thru the insert would allow you to use the insert with Richard's method of drawing the bearing into place rather than hammering it in. Or you could chuck it all and haul block,cam,and bearings to a reputable machine shop for fitting. Interior dimension of bearing will probably need to be honed or reamed to size after installation anyway. If they screw it up at least you can holler at someone other than the face in the mirror. Hang in there!|
Dan Craig TD/C21793 (Margret)
|I could not help but notice that there is a special reamer 8G351 for the front camshaft bearing, shown on page Q6 of the WSM.|
I have changed my front cam bearing twice and in each instance, I put the bearing in the freezer, and gently warmed the area around the hole, with a gas torch. I then drove the bearing into place using a simple wooden mandrel I made on the lathe.
... worked in 1965 and again in 1980. Should work again! Its the rear bearing that's a real monster!
|Gordon A. Clark|
|I don't know why none of this dawned on me since it's a split bearing. I guess I'm too used to whole bushings that just need to be driven in evenly. Thanks all.|
|Don't know about where your at, but our Advance Auto parts loans tools, including a cam bearing installer.|
|I just did this same task about an hour ago. The new Moss bearing would not go in so I took a hone to the block. A hone normaly used for brake cylinders. I honed and honed, took about an hour or two but finally got the bearing to go in. I also used a 8" piece of 2x4 and a brass hammer to set the bearing. I used an old rear cam bearing to remove the front bearing if it was still too tight and honed some more. Finally I used the old rear bearing to seat the new front one. Luckily the oil hole lined up perfectly.|
I put the middle and rear bearing in the freezer until it was time to put them in. The rear was very easy the middle was a tad tough so I hone it too. I put the middle bearing on the cam after inserting the cam half way in the block.
|Oh, this is looking like more and more fun.|
|Did you get bearing in? |
Sounds like we're both at about the same stage of engine rebuilding. The latest obsticle was the middle main bearing. It was a tad to wide, but a flat surface and a sheet of 320 sand paper fixed it. The end float is about 0.001.
|Richard: Might be well advised to avoid changing block dimensions to make bearing fit.If you resort to sanding,polishing,honing,cutting,welding,laser beams,or tactical nukes,future owners and machinists would probably appreciate the mods be made to the replacable component (ie-the bearing). Can also cut down on righteous cussing of POs-and wouldn't that make the world a nicer place?|
|End float of .001" is not correct. .I believe + .005 more (+ .010" - ) Is needed.I.E. (.006" to .012" or so, check the W. S. M.|
|Ok, It's in and so are the middle and rear bearings, plus the camshaft. I did it a little differntly, though the middle and rear went in with no problems, no freezing, etc.|
For the front I had to get a replacement. Instead of honing anything, I filed the ends of the split bearing until it seated itself with folding over. I used the old rear bearing to keep it expanded. Everything lines up and the camshaft is sitting pretty. I'll measure endfloat tomorrow. Also looks like I have all the caps and plugs, except the one for the rear bearing so I'll have to order that too.
Thank you everyone for your suggestions.
This thread was discussed between 04/07/2007 and 14/07/2007
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