More Uses of Heat

super heating a retaining clip

A retaining clip glows cheerfully

In this industry MGA & MGB three synchro transmission overhauls are a basic repair like a tune up or a brake job.  All of them eventually suffer from the same failings; bad second gear synchromesh and heavy wear of the layshaft and needle roller bearing assembly on the first & reverse end of the cluster gear.  When you’re in there, it’s a good practice to replace the rest of the bearings and synchronizer baulk rings while you’re at it.

replacing an MGA transmission mount

Easing-in the transmission mount

The needle bearing assemblies in the cluster gear, there are three of them, are retained by spring steel clips which were always the Devil’s work to remove.  For years I thought there must be a better way than using a couple of awls.  Well there is, and this is it.  Just flash them with the oxy-acetylene torch for long enough to cause them to glow red, which anneals (softens) them, and you can practically remove them with a wooden tooth pick.

removing exhaust manifolds

Patrick already used heat

MGA transmission mounts are a press-fit in the tailcase, and I’m sorry to have to tell you that the quality control has been quite up and down on these the last few years.  I first noticed a problem when a mount with too much O.D. broke the a tailcase housing a few years ago.  Now we’re much more careful. Some times we turn ’em down a little bit, but a little heat judiciously applied will also expand the aluminum housing enough for the mount to press in easily.

MGA TX speedo pinion retianer

Using a thread tap as an extractor

The MGA speedometer gear housing has an oil seal which is retained by a sleeve and is often overlooked.  A 1/2″ 13tpi tap makes an ideal extractor for the sleeve.  Thread your 3/8″16tpi tap into the oil seal and tap it out with a drift.  BTW: This oil seal (AAU 2304) isn’t in the transmission overhaul kits some catalogue vendors sell, you’ll need to order it separately.  It’s also known by the Jaguar part number C32592.  Same seal.

Boring a TX top cover for a dipstick tube

Butch installs a hole for a transmission dipstick

Last Friday Butch & John wrestled the new overdrive transmission into the red TR3 from Texas.  The new one is actually a four synchro unit with a oil check & fill plug on the side, but sadly no provision for an owner/driver friendly dipstick.  After all, how many people have a lift in their garage ?   The Brits knew that when they designed these cars, only later on they forgot.   Switch locations being different, we couldn’t use the old cover.  But Butch fixed that on the Bridgeport.

Saturday morning Patrick and I, but mostly Patrick, changed the head gasket on my winter beater MGB GT, so on Monday morning I decided to hike over to the Post Office to assess the state of the repair.  The car ran fine, but it was virtually the only one on the road.  Four studded snow tires make it safe.  Just forget about those three season radials, even if you have four wheel drive, your car needs them, too !

MGB GT on a snowy road

3rd gear descent: Monday morning on a snowy road in the MGB GT which has a new head gasket now.

This entry was posted in This week at the shop. Bookmark the permalink.