Technical Tips

Wiring loom warning.
My 1970 MGB GT was recently started after a three month Winter rest. The left hand indicator remained lit, even after removing the key from the ignition. I checked the wiring loom, tracing from the fuse box to underneath the car. I found the problem underneath the starter motor. The wiring loom had been secured by metal clips to the heavy 12 volt cable from the battery to the starter solenoid. Over time the metal clip had worn through both the 12 volt cable and the wiring loom insulation. This short had caused the left hand indicators to remain lit. There had been local overheating of the wires and the insulation of several wires in the loom had melted together and a three inch section of one wire was completely exposed. I do not know if these metal clips were factory fitted, but I advise all MGB owners to spend a few minutes underneath the car to check if their wiring is at similar risk. I replaced the three metal clips with plastic cable ties.

Guy Nicholson

Zenith Stromberg
I bought my MGB from a friend in Minnesota, it is an American specification roadster, hardly used and in very good condition. Although the catalyst has been removed, the car retains its original Stromberg carburettor and I have fitted a stainless steel exhaust system. Recently my MGB let me down for the first time. At first, I thought it was the fuel-cut-off-valve, which is fitted to this car. Even after removal of the valve the car still would not run. By now fuel was pouring from the vaporize loss system. After opening the carburettor, a Zenith Stromberg CD 150, I discovered that the float had broken off and this was causing the problem. After fitting new rivets and setting the float at the right level, the car was almost alright again. Although after having the timing checked I also discovered that the vacuum advance on the distributor was not functioning correctly, once this had been fixed the car then ran better than I had ever experienced.

Marco van der Hel

Marco’s American spec MGB roadster

Wet Carpets
If when getting into your car after a downpour, you find the foot well carpet soaking wet. There may be several causes, a leaking soft top, a poorly fitted screen rubber, or the bubble seal fitted around the door aperture. If this seal is a bad fit, water will bypass the sill lip and capillary over the sill and soak into the carpet. To remedy this, you can first remove the seal, it is a press fit, and check to see if there is any damage. Look for splits and examine the steel spline, if it is rotted, buy a new seal, because it will cause far more damage than it costs to replace. Small splits can be glued and repaired, if the seal is tired or has become a loose fit making a bad seal. Wash it carefully paying attention to the U channel of the seal, dry thoroughly and refit, using black silicone sealant applied to the U channel – not too much! Masking tape can be employed to hold the seal in place whilst the silicone sets.

Gary Sallows
Blandford mobile welding.

How do I get oil into the gearbox
At first I experimented with different types of funnels and a milk can which I considered “surplus to requirements” in the kitchen. There never seemed to be sufficient clearance above the tunnel to gain decent access, so some oil ended on the garage floor or even in the footwell. So why not try a “technical” approach:

Fitting a suitable length (about 2ft) of clear plastic tube to the nozzle of a common oilcan-with-pump creates a custom made “gearbox filling device”.

For obvious reasons, the tube should be securely fastened to the pump, e.g. with a hose clamp. I’d advise using a double-acting pump. That is, one that works upside down or right side up, to avoid problems if the pump gets tilted a bit.

Acting on the pump lever, the flow of oil can be observed through the clear tube. My pump is a bit slow, so it takes quite a lot of “shots” to top up the gearbox. On the other hand, this prevents overfilling the box, which might result in a well oiled clutch. When changing the gearbox oil, the pump might be replaced by a suitable “squashy” bottle.

Wolfram Halupka

Mystery clonk
My MGB GT has been haunted by an increasingly unpleasant clonking noise which appeared to come from the offside rear suspension. It took me months to trace the source of this noise. In an effort to locate the noise, I unpacked and repacked the area below the rear deck several times, and finally removed all the tools and other odds and ends. The clonking noise persisted despite all these changes and I began to despair about tracing the cause of the noise. The sound only occurred when riding over bumps, therefore I concluded that the shock absorber must be the cause. However, there were no signs of a leak and the shock absorber was functioning correctly. The drop link was also sound with all bolts tight and the bushes in good condition.

Despite this, I decide to change the shock absorber anyway. Replacing a rear shock absorber is a straightforward task, provided the bolts come undone and the drop arm bolt will separate from the damper lever. After fitting the new shocker it functioned perfectly and although the ride was unaltered, the clonking noise disappeared at last.

Mike Malig