Hi John,
When you say 'grabby', are you referring to the action of the clutch?
The gearbox itself is full of rotating parts, so unless something is
really banging around and about to tear itself to metal shards, grabbing
won't come from the gearbox.
TDs are well known for grabbing, though. Oily clutch, loose clutch
linkage, soft engine mounts, loose stabiliser bar, loose u-joints, loose
U-bolts on rear axle are the most likely culprits.
First off, drain and refill the gearbox. Redline MTL 90 works well.
90w gear oil is specified by MG, but that was specified 50 years ago.
Whatever you use, something new is better than thirty year old stuff.
Change rear axle oil while you are under the car. If you use Redline,
there is a gear oil for the axle, name of which I forget.
Yes, you can change the engine mounts with engine in the car. Front is
easy. Rear is trickier but can be done. Compared to doing this on MGB,
it's a piece of cake. Transmission tunnel must be removed. Bolts holding
it down are of different lengths. Make a map of some sort so they go back
into the same holes. The little bolt that holds rear of gearbox to
chassis looks like the fork end of a turnbuckle. Often they are missing;
no trouble to replace that, but if the tab on the gearbox to which the
thing attaches with a clevis pin is missing, its replacement means a bit
of welding or some clever machine shop work.
The clutch rods can be 'boogered up', and very well buggered too.
Hanging down in the dust kicked up from the road, then coated with oil
dripping from the engine, an excellent grinding paste is made that causes
rapid wear on all these connections. If you pull the clevis pin at any
joint, you will see that it is worn and the joint is worn. Solution is
to get new clevis pins, hardened, fill the worn holes and to have them
drilled to fit the pins. The connection at the base of the pedal wears
at least as much as those that are more exposed. Inside the pedal box,
dirt builds up and stays in place instead of being rinsed away by rain
splash. When I rebuilt mine, I put the rubber boot from an MGB master
cylinder onto the clutch shaft in an effort to reduce the dirt being
flung into the pedal box. Will let you know in 20 years if it made any
difference. The pivot pin on the sump wears a lot. It can be swapped
with the one on the other side of the sump, but sump must be removed to
do the job as the thing has a nut on the inside. The pivot lever has a
bushing that can be replaced. When you have it all right and tight,
there will be no slack in the joints of all the pieces from pedal to
clutch lever; all will move smoothly without binding. My thought on
this is that keeping the joints clean is best thing that can be
done--spraying them with WD40 a couple of times a year to rinse off the
grit and to give a bit of lubrication is about all one can do, though.
Having done those things, just work your way through the list. And, if
you have the same experience I did, you will feel good about all the fine
things you did and the clutch will grab as fiercely as it ever did. Just
try to be gentle with the grabbing, as the half-shafts have been known to
break from rough treatment.
Bob
On Tue, 20 May 2003 08:25:42 -0500 "Gunnell, John" <gunnellj@krause.com>
writes:
> Just drove my TD 400 miles this weekend including four laps around
> Road America. No real problems. Couldn't keep up with the Porsches
> and Vettes, or even the restored TF, but it was sure fun.
>
> Shifting gears is far from smooth and silky, especially first
> gear. First has been "grabby" since I got the car last fall. I
> thought I was getting used to it, but once in awhile the car will
> really lurch out of first and shake all over.
>
> Other than taking it out and rebuilding it, any tips? I assume it
> would pay to take the 30-year-old gear oil out of the box and refill
> it with new lubricant. Are there any special blends that work
> particularly well? Are there any other things that can be done
> without removing the drive train? Can new mounts be installed with
> the engine and trans in the car? T
>
> Also, the shop that did my tune-up said the clutch rod could be
> "boogered up." I really can't see any damage, but maybe I'm not
> looking at the right thing. Once in awhile I'll get in the car and
> it won't move, but after a little rocking and shifting, it's fine
> again. What's this all about?
>
> Any good free advice will be freely accepted. Thanks to you all
> for help in the past. The car is getting better and better.
>
> John Gunnell
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