jumps out - not a new difficulty!
Edward Corbett (Teal
Blue 1916) from London SE has recently bought an MGBGTV8 and posted a message
on the V8 Website bulletin board seeking help with his reverse gear slipping out.
Corbett's posting said "I have just bought an original MGBGTV8 and it
runs beautifully apart from when one is reversing, and occasionally in second
gear, the car will quite often slip out of reverse gear. Has anyone else come
across a similar problem and if so is there a remedy?"
by chance Victor Smith (Harvest Gold 1089) was reprocessing Volume 4 of
the V8 Workshop Notes series the night before and had seen a Note 121 on that
very topic contributed by Mick Westrop back in 1983, and a reference to an earlier
Note 27 from Peter Laidler in Volume 1 back in 1979! Copies of both Notes were
put up on the V8 Website for Ed to read. By the way Volume 4 is the last volume
to be reprocessed as part of a project to put the whole of the V8 Workshop Notes
series on a single CD for distribution to members by April 2003 in time for the
V8 25th Anniversary.
response on the bulletin board came in from Gavin Bailey (Glacier White
0199) from Surrey - "I had this problem when I fitted a new rubber boot
that sits underneath the gearbox gaiter. The new rubber boot was far stiffer and
less pliable than the old one and tended to pull the gearbox lever back to dead
centre. It may be that there is some other problem with the gearbox, however a
stiff gaiter could be a contributing factor". Well it is certainly the
least expensive possible common cause to check first - it is essentially the cause
outlined by Mick Westrop in his Note some twenty years ago.
Gavin Bailey (Glacier White 0199) from Surrey . (Photo: Victor
came a posting from Dave Wellings (Black 0974) from Yorkshire who acknowledged
a stiff gaiter was one cause but then outlined further investigations as follows
- "Get the centre console out of the way, remove the gearknob and gaiter
and then look to see whether the gearstick touches the "hole" in the
second or reverse positions, or top gear. There is a fibre layer around the hole
and if there is any contact you may need to grind away some of the surround to
get clearance. Remember that the gearbox moves slightly under load, which will
close the gap".
then touched on sloppy gearbox mountings which can cause the rear end to drop
or the box to move about excessively. This will knock the gearbox out of gear.
"If you do all these checks and it is still no better then the next thing
I would look at are the detent springs. Now I working from memory as it is ten
years since I stripped my gearbox but there are three bolt heads just aft of the
bellhousing. Under those bolts are the three detent springs and balls. One each
for 1st/2nd, 3rd/4th and reverse - three selector rods. It may just be possible
to replace those with the gearbox in place".
another possible cause might is slop in the gearbox itself and the primary culprit
I suggest would be wear in the laygear thrust washer. This allows the laygear
to move fore and aft - with the power on/off which may kick it out of reverse
gear. Otherwise it may be general bearing wear, or selector fork wear and the
only solution left is to take it out and have a look".
Allen (Teal Blue 2101) was asked for his views on the reverse gear difficulty
as he has a long
of working on MGBGTV8s ever since the early development cars. He has probably
seen more V8 gearboxes than most V8 enthusiasts as he was in Rectifications Department
at the Abingdon Factory for 27 years which covered the development and production
of the MGBGTV8 and then later ran his own MG maintenance and repair business in
Abingdon before retiring to Cheshire eight years ago. "I can add a few
comments to the notes on the problem of the V8 jumping out of gear. As the car
jumps out of reverse and second, I think it is more likely to be caused by the
gaiter than anything more serious inside the gearbox. When we were producing the
V8 this was a common problem and was usually caused by the incorrect fitting of
the gaiter. There is always a tendency for the gear lever to be slightly to the
rear of centre of the hole in the transmission tunnel so make sure the seam in
the leathercloth gaiter is to the front of the lever - that is towards the fascia.
Also when fitting the gaiter make sure that both the ribbed rubber and leathercloth
gaiters are fitted under the console directly onto the carpet, not on top of the
console under the chrome ring. We found this usually cured the problem on cars
at the Factory and I have cured quite a number that way since. The lower the gaiter
is down the lever the less chance there is of the lever fouling it".
quote an extreme case of this problem, I fitted a 1977 MGB gear lever which has
a silentblock bush fitted to a V8 to cure gear lever "zizz" and had
to cut the tunnel and weld in new nuts, then reposition the console to line it
all up. I also fitted the same type of gear lever to my V8 (Teal Blue 2101) and
that went straight in with no problems so there is obviously quite a difference
in position between various cars."
Geoff Allen (Teal Blue 2101), the V8 Historian & Archivist, was
at the Abingdon Factory when the MGBGTV8 was developed and produced, and in Rectifications
Department he sorted out the faults and niggles from the production line and road
tests. (Photo: Victor Smith)
the subject of detent springs there was a suggestion at one time of a modification
to the three fork rod plungers which are operated by the detent springs and drop
into the recess in the fork rod to hold it in gear. This modification was to cut
the bottom off the plungers and fit a steel ball in its place to make for a crisper
gear selection! I don't think this was a very good idea as the plunger has around
1" bearing surface whereas the steel ball has only a minimal bearing surface
and can hammer the aluminium hole in the case and lead to a sloppy location of
the lever fore and aft. I have found this problem on one car in the past and removed
the balls and refitted the plungers which cured the problem - luckily the owner
said he had fitted the balls so I knew what to look for. So having talked a lot
of balls I will now sign off!" Typical jovial false modesty from Geoff
The outer leathercloth gaiter covering the inner ribbed rubber gaiter - a likely
cause for reverse gear jumping out. (Photo: David Waterton)