Gearbox woes

Discuss mechanical problems here.

Moderator: Moderators

ndevans
Minor Addict
Posts: 747
Joined: Fri Mar 03, 2006 11:56 am
MMOC Member: Yes

Re: Gearbox woes

Postby ndevans » Mon Apr 29, 2019 10:52 pm

ianmack wrote:
Mon Apr 29, 2019 7:43 am
I certainly wouldn’t use that first gear again, those teeth are disintegrating. I had a tooth come off a motorcycle gearbox a while ago and the gearbox seized completely, always an unpleasant experience especially on a bike.

I have some spare gears and might have one.
PM sent
cheers N
'69 Traveller, 1275, discs.

biomed32uk
Minor Addict
Posts: 624
Joined: Mon Feb 03, 2014 5:16 pm
MMOC Member: Yes

Re: Gearbox woes

Postby biomed32uk » Thu May 02, 2019 8:48 pm

A stout tie wrap is all you need, and as said do it inside a plastic bag. make sure to line the gear up to the hub in the correct place. Otherwise you won't be able to get 2nd gear and the whole lot has to come apart again.

ndevans
Minor Addict
Posts: 747
Joined: Fri Mar 03, 2006 11:56 am
MMOC Member: Yes

Re: Gearbox woes

Postby ndevans » Thu May 02, 2019 9:10 pm

So this arrived today.
IMG_20190502_205818~2.jpg
IMG_20190502_205818~2.jpg (963.52 KiB) Viewed 429 times
I rang the people who supply these to Minisport, a company called Guesswork. They confirmed that it is suitable for a Minor 1098 1st gear hub. At £30 it's not cheap, but I reckon if I try the cable tie method I stand a good chance of losing the balls and springs.
It certainly works ok. It's best to assemble the springs in the hub first, then place it with the springs closest to the bottom, in the tool. You then need a small screwdriver to push the spring in, whilst forcing the ball with your thumb over it in the recess in the tool.
When all 3 are in, you place the 1st gear wheel deep flange side down, over the hub. You have to ensure that the recessed tooth on the inner ring is aligned with the detent plunger in the hub.
Then place the whole thing in a clear plastic bag, and twist the tool clockwise. The balls and springs are now fully compressed. You then turn the assembly upside down, so the tool is on the top, and, still in the bag, give it a sharp tap on the floor. The hub should then slide out of the tool and over the balls and springs. Try carefully taking the tool off, still inside the bag, and the springs should still be contained inside the hub/gear assembly.
cheers N
'69 Traveller, 1275, discs.

ndevans
Minor Addict
Posts: 747
Joined: Fri Mar 03, 2006 11:56 am
MMOC Member: Yes

Re: Gearbox woes

Postby ndevans » Fri May 03, 2019 11:26 pm

Tonight, I 'ave mostly been puttin me gearbox back together.
IMG_20190503_224708~2.jpg
IMG_20190503_224708~2.jpg (1.25 MiB) Viewed 378 times
cheers N
'69 Traveller, 1275, discs.

ndevans
Minor Addict
Posts: 747
Joined: Fri Mar 03, 2006 11:56 am
MMOC Member: Yes

Re: Gearbox woes

Postby ndevans » Sat May 04, 2019 4:44 pm

More progress, going smoothly currently *touches wood*!
IMG_20190504_164143~2.jpg
IMG_20190504_164143~2.jpg (2.1 MiB) Viewed 347 times
cheers N
'69 Traveller, 1275, discs.

ndevans
Minor Addict
Posts: 747
Joined: Fri Mar 03, 2006 11:56 am
MMOC Member: Yes

Re: Gearbox woes

Postby ndevans » Thu Aug 22, 2019 11:36 am

Well, the reassembled gearbox and rebuilt engine (see separate thread for engine) have been in the car, and it's done about 100 miles now.
I have two concerns.

1) the gearbox whines in 1st, 2nd & 3rd. Seems ok in 4th, but I've not taken it above 50mph yet.
2) there's a rhythmic clicking sound, a bit like something rubbing, when accelerating in 1, 2 & 3. It sounds a bit like a slightly loose tappet, but if I hold the gear lever, it diminishes noticeably.

To recap, I have done the following to the gearbox:-

1) Replaced the bell housing with a spare, due to the bolt flange being broken
2) fitted new 1st & 3rd motion shaft main bearings, shims and 1st motion shaft needle bearing
3) fitted a new layshaft (but not laygear), needle bearings and thrust washers (measured for the correct endfloat)
4) fitted a new 1st gear

The gearbox extension and remote control have not been touched, apart from removal and replacement from the bell housing.

I've also fitted new detent balls and locking plungers, but only because I lost them!
The gearbox has been filled with some spare 15W40 engine oil for the purposes of running in, with the intention of changing it for 20W50 after 500 miles.

So what could cause the whine in gear 1/2/3, or is it too be expected when running in?

What could cause the rhythmic clicking that quietens on holding the gear lever? The anti-rattle plunger and spring are present, I was careful to fit it on reassembly.

Lastly, am I right in thinking that the laygear is in constant mesh, and turns all the while that the 1st motion shaft is turning?

Cheers N
Last edited by ndevans on Thu Aug 22, 2019 12:57 pm, edited 1 time in total.
cheers N
'69 Traveller, 1275, discs.

les
Minor Maniac
Posts: 7281
Joined: Tue Feb 12, 2002 12:00 am
MMOC Member: Yes

Re: Gearbox woes

Postby les » Thu Aug 22, 2019 12:55 pm

Regarding the whine that you mention, it’s often the case with mixing gears old and new, teeth bed in together in gear sets. Not familiar with your other issues.


ndevans
Minor Addict
Posts: 747
Joined: Fri Mar 03, 2006 11:56 am
MMOC Member: Yes

Re: Gearbox woes

Postby ndevans » Thu Aug 22, 2019 1:28 pm

les wrote:
Thu Aug 22, 2019 12:55 pm
Regarding the whine that you mention, it’s often the case with mixing gears old and new, teeth bed in together in gear sets. Not familiar with your other issues.
That's what I thought at first, and I could understand that if I'd replaced 2nd and 3rd gear and/or the laygear, but I've only replaced 1st gear.
cheers N
'69 Traveller, 1275, discs.

les
Minor Maniac
Posts: 7281
Joined: Tue Feb 12, 2002 12:00 am
MMOC Member: Yes

Re: Gearbox woes

Postby les » Thu Aug 22, 2019 2:35 pm

Yes, misread layshaft / laygear.


ndevans
Minor Addict
Posts: 747
Joined: Fri Mar 03, 2006 11:56 am
MMOC Member: Yes

Re: Gearbox woes

Postby ndevans » Fri Aug 23, 2019 9:41 am

Could a misaligned selector fork be the cause of the whine?
cheers N
'69 Traveller, 1275, discs.


Who is online

Users browsing this forum: No registered users and 24 guests