Tech Tips: Summer 1989

Familiarity Breeds Blindness
By Larry Dussack
Friendswood, TX

Note above arrows

Have you ever had your TD or TF quit on you for no reason? A stupid question, I know, but after what I just discovered, a valid one…My TD would quit after about 3 days of normal driving. It appeared to be electrical, so I would check the distributor every time. After years of this, I would open the hood and move the tach drive out of the way to see the distributor better. Finding nothing wrong, I would check fuses, fuel level, etc. and then it would start right up again. After a number of these incidents, I finally got it through my thick head, saw what was happening, and reset the distributor so the tach drive box would not fall against the contact nut and short it out…again.

(Since T-series distributors incorporate a helical drive gear which meshes with the cam shaft, it is possible to have the distributor timed correctly in any of4 different positions, 9CP apart. Reference to any factory illustration will show that the distributor should be situated so that the ignition coil feed terminal is in the 4 o’clock position when viewed from above. This insures that the tach cable and or tach reduction gearbox can’t ground out the terminal-Ed.)

T-Series Aluminum Valve Cover Noise
By David Rosser
Richboro, PA

The following might be of help to MGT series owners with cast aluminum valve covers.We began to notice excessive valve gear noise (even by old MG standards) in our 1952MGTD. Pulling the valve cover and re-setting all clearances did not help; the noise was worse! A complete tear-down of the top and valve gear indicated no abnormal wear and all oil ways open. Back together and re-set gaps. The noise was worse!

Then, as I started to pull the valve train again so that I could pull the tappets and push rods, I noticed that the inside of the valve cover had a series of half moon gouges all down one side. Almost every valve spring top was hitting the valve cover. The rear stud of the two that act as anchors for the valve cover was a) loose and b) bent slightly. As it loosened more, it caused the valve cover to shift to the left. Each time I replaced the cover and black knob on top I caused the cover to shift a bit more and thus cause more spring to cover contact. With the original steel cover it might not matter, but with the extra aluminum thickness, you have nasty contact and nasty noise. A full time mechanic might have caught this problem quickly, but then again, we are not full time mechanics!

(Due to the extra thickness and enhanced sound deadening qualities of aluminum value covers, a bent or loose securing stud certainty can cause the problems that Mr. Rosser writes about. Replacing or straightening the studs mill usually cure the problem, but if the valves still hit the valve cover, you can easily correct this by taking a die grinder to the offending spots on the inside of the valve cover. Our TC and TD coffin style valve covers, as well as other period accessory valve covers normally offer far superior sealing for the valve cover gasket and allow for removal and replacement of the cover without replacing the gasket, particularity if gasket cement is only used between the gasket and the cylinder head —Ed.)

Front Suspension Rust Problems
By Gordon Buckman
Seattle, Wa

The left front is illustrated.here. The same is true at the inner ends of all four lower control arms.

After 23 years I just replaced the bushings on the front suspension on my 1966 TR4. I would like to pass on a tech tip that solved a tough problem for me.

The steel sleeve on the front of the lower wishbone shaft had rusted to the shaft. After trying everything from tapping with a hammer to WD-40, I loosened it by the following method.

Using a sharp chisel, place it against the shoulder of the shaft and the apparent end of the bushing. Rap the chisel with a hammer two or three times and the bushing will be forced towards the end of the shaft. Once it has broken loose, a few taps will free it. Be careful not to pound too hard and nick the shaft!

(This is a common problem with the TR2 through TR4. When the lower control arms and nylon bushes are removed, this steel bush is almost always stuck firmly onto the fulcrum pin —Ed.)