Welcome to our resource for MG Car Information.
Triumph TR6 - Gearbox Removal
|As indicated in previoud posts I am about to change the clutch on my 75 TR6 and am working through the steps per Haynes and the Triumph factory manual. I am at the point of removing the gearbox and envisage difficulties even with two people since most of the weight appears to be in the area under the dash. Are there any secrets that I should know? Also, any tips on gearbox replacement would be appreciated - lining up the shaft whilst maintaining alignment.|
I have done all this before on my previous 73 MGB but it was simple as the engine & gearbox had been removed as an assembly.
My first suggestion would be to put away the Haynes manual - I don't know what car they are describing, but it isn't a TR6! I wasted a couple of hours staring at the pictures before I realised that the pictures were only giving a vague idea of what a slave cylinder looks like, rather than showing where the TR6 slave cylinder is mounted...
To remove the gearbox I used one of my most useful tools - a friend who trains NFL players and spends several hours each day lifting weights for fun! The gearbox is surprisingly light thanks to the aluminium casing, but as you say, most weight is under the dash. The way I did it was to lie under the car to support the weight of the front until the shaft was clear of the engine, and then he lifted it out through the passenger door. If you have overdrive (I don't) then I would think it is a lot heavier and more awkward. Replacing was just the same in reverse, and went surprisingly easily, I thought. If you have the plastic tool I suggest you align the splines with those on the shaft to make sure it goes in easily. The hardest part for me was removing all of the nuts and bolts holding the bellhousing to the engine on my own. If you have an air ratchet then it is much easier - hold a spanner on the bolt head in the engine bay and reach inside to the air ratchet to remove the nut (I just joined all of my extensions together to make this possible). If you have someone to help it would be much easier.
Hope that helps
What is the purpose of the open rectangular slot on the passenger side of the transmission? Is it an inspection hole or am I missing a rubber plug here?
I am not really sure what that slot is for. I assumed it was for ventilation, since the clutch has the potential to get rather hot. There was a small hole at the bottom of the bell housing which I guessed was to let the oil escape (after leaking through the gearbox front seal which I chose not to replace - don't ask me why, as I have no idea!).
Many thanks for your input. I was uneasy about lying under the car whilst the g'box was being moved. I enlisted a friend to help and we managed to remove it by using a second trolley jack to take the weight whilst we both pulled and lifted from inside. My car has overdrive and the rear supports were nothing like the ref pages - we were unable to remove it and this became the main obstacle to pulling back for shaft disengagement. It has since been removed and we know that it can;t go back in until the g'box is back in place. Stay tuned.
Get two 4 inch long bolts, (same size as the bellhousing to block bolts.) and cut the heads off. I used a hacksaw, and also cut two slots across the end to use a flat tip screwdriver to run them in. Place them in the top outer bolt holes on the bellhousing, and when the tranny is ready to slide out, it slides back on the bolts. Support the rear of the engine with a jack, probably need to lift the back of it a bit for the tail of the trans to clear the tunnel.
This also helps greatly when you are re-installing the trans. If memory serves me correctly, Rick Orthen or Rick Crawford mentioned this a few years back. Last time I pulled my trans out, it took about two hours. I became rather proficient, but that's another story I won't go into right now. I need some scotch just thinking about it!
|one other point needs to be mentioned, put the trans in a gear so you can turn the tailshaft flange to line up the imput shaft with the clutch disk when you are putting the trans back in.|
|The back of the engine MUST be supported for the re and re and the support be left in place while the tranny is out of the car. Yes Rod my second removal of the tranny was my second guessing myself. I guess you could say it made me more proficient in removing the tranny.|
Barry, there are 2 different versions of rear tranny/OD support. One for the A type and one for the J Type. Mine is the A type and it needs to be fully removed to pull the tranny.
Do not use the bell housing bolts to "pull" the tranny back tight to the back of the motor. It should slide up very tight.
I think the following is true for all situations as far as the A type OD is concerned.......The bolts securing the prop shaft UJ flange to the OD flange are flattened on one side. Obviously use new lock nuts and a little Loctite.
|It is tight, but I have pulled transmissions with A-types out of a TR6, if it is a non-OD transmission, things are easier as you have less bulk hanging off the back side of the transmission. I ran a jack under the transmission and completely loosed/removed bolts from the rear cross support (but did not remove that cross support)then forced the propshaft as far back on the splines as it would go and pushed it as far as the tunnel would allow down and to the left side of the car. This yielded just enough clearance for removal of the transmission with the A-Type OD unit.|
Can't say exactly how things would work on a J-Type OD as I have never removed one of those. Of course, the rear of the engine was supported during the R&R operations and the whole time the transmission was out of the car.
|Or, get a teenage kid with a strong back! When Clive and I removed the motor from my car last year, we were debating how to get the transmission out. I went and got my then 15 year old son to help us, and he just laughed at us old guys, went over and picked it up out of the car and asked me where I wanted it. Did I mention he is now about 6'4 1/2" and 185 pounds?|
Here's an important tip that everyone should know about TR6 gearbox installations.
Two of the bell housing bolts are meant for 3/8 diameter shoulder bolts or dowels - the purpose being to properly locate the center of the flywheel with the center of your gearbox input shaft. Too often, these are missed; most people use 5/16 bolts only in all the locating holes, which results in an eccentric misalignment between the flywheel pilot bush and the aforementioned input shaft. The net result is a premature failure of your release bearing, or my case, a pilot bush that was machined by the gearbox shaft to the point of failure (evidenced by a loud, squealing or machining sound when I initially touched the clutch pedal).
To avoid this, go to a fastener retailer and buy two 3/8 diameter shoulder bolts with 5/16 threads. Make sure the shoulder is long enough to properly engage both the bellhousing and the engine plate. You might have to buy a longer shoulder than necessary and add several washers under the head to properly position these bolts. Put these shoulder bolts in BEFORE you tighten the other 5/16 bolts.
Some have suggested using dowels instead of the shoulder bolts. I understand that this may not provide enough clamping force between the engine plate and bellhousing - because Triumph used to do this with the early TR6's and had a number of bellhousings come loose because there were too few fasteners.
Note that I know of no TR6 parts catalog today that shows the use of these shoulder bolts. They were used initially, but they seemed to have been missed over the mists of time.
There's a lot of talk on the web about faulty TR6 release bearings. I suspect, in reality, that the bearings were fine. The release bearing problems were probably caused by this misalignment if the two locating 3/8 bolts aren't used.
1973 TR6 in Winnipeg
with a freshly installed and properly located gearbox
|Many thanks for all the useful comments. The clutch was a B&B - the subject of some discussion when heavy pedal force had been experienced. My OD is a type J. As often reported by others, the infamous taper pin was sheared and an access hole had to be drilled opposite to enable removal using a punch. The new Sachs clutch has been installed together with new cross shaft, fork and release sleeve/bearing. Gearbox reinstallation may have to wait a few days before I can put some of the advice to good use.|
|I used ready-rod in the two lower bellhousing bolt holes (one on each side). Nut on the engine side of the ready rod prevents the rod from slipping out.|
This allows you to work with tranny away from the clutch from bottom and top without the tranny falling.
I removed and re-installed my tranny twice by myself. My wife supervised.
Not my idea but one I picked up on some time ago.
As already noted it is necessary to support the back of the engine. If, having removed the bottom bellhousing bolts only, this support is a 4 * 1.5" timber which extends forward under the sump and backwards by about 18" you will find you have a nice ramp / slipway to slide the box along in and out.
Hope this helps somebody.
This thread was discussed between 13/04/2007 and 20/04/2007
Triumph TR6 index
This thread is from the archive. The live forum is active now.