24 replies to this topic

[Sharks]

Hi all,

 

Hope someone can give us an easy fix for this, but we're suspecting an engine out job at this stage...

 

Since putting the four-speed DAM5626 in the Moke I've had some difficulty selecting first gear from a stop. Looking around here and other sites it sounded like this was relatively common and I'd chalked it up to incorrectly measuring the baulk ring clearance or something of that nature. At any rate, if the car was just slightly moving I could always select first, and if I selected second, then first, that usually worked too. Very rarely I'd select third or fourth and row back to first, but I've done roughly 20,000kms this way and have had no other issues.

 

I drove three hours home on Friday, parked up in the shed and went to start the car last night to go out for dinner. All of a sudden I can't select any gear, whether the car is rolling or not! Had to take the backup car.

 

This morning I put the Moke up on jacks, started it up, and noted that while I can select gears, the wheels are turning slightly (and sometimes intermittently) even with the clutch fully depressed. Maybe this is why I always struggled to select first?

I backed off the overthrow nuts so they're nowhere near the wok, and made sure I had 20 thou against the stop when pulling on the clutch arm. The arm certainly looks like it's moving more than far enough to disengage the clutch, and when the clutch is all the way in the engine speed is decreasing, so it should be well and truly disengaged if it's putting pressure on the thrust washers like that. Still, the wheels turn when the clutch is depressed.

 

What could be the issue? We keep coming back to the primary gear. Either the clutch disk is bound on the spline and is not coming away from the flywheel, or the primary gear is bound on the crank and is not spinning freely when the clutch is released.

Before I went to the trouble of pulling the car to pieces to investigate, I thought I'd ask here if anyone has any other ideas.

 

Thanks in advance,
Sharks.

[Pigeonto]

Primary gear to crank most likely.

Which isn't necessarily engine out unless you prefer to or can't get the clutch off the crank.

[nicklouse]

How much travel at the slave cylinder?

condition of the arm and all the clevis pins?

[Sharks]

Primary gear to crank most likely.

Which isn't necessarily engine out unless you prefer to or can't get the clutch off the crank.

I can look at the primary gear without taking the engine out, but I can't do anything with it, can I? I'd need to take the flywheel housing off.

Currently the engine is still in the car but I've got the wok off last night. My 1 1/2" deep socket won't fit on the flywheel bolt because the body is in the way, so I'll have to buy a regular 'shallow' socket today and try to get the flywheel off tonight or tomorrow. If it's just a clutch problem maybe I can fix it in the car, but if it's a primary gear issue I think it will have to come out, no?

 

 

How much travel at the slave cylinder?

condition of the arm and all the clevis pins?

Plenty, and very good. Like I say, the engine was slowing due to overthrow, so I don't think it was an issue with the clutch adjustment.

I have had two arms snap their balls off in the past, but this time there was nothing I could spot wrong from the outside.

[Spider]

Check how much movement you have of the Backing Plate.

Engine off, open the Timing Inspection Cover on the Clutch Cover (Wok). Put the engine in 3rd or 4th and push it back and forth until you have a Diaphragm Bolt Head in the Inspection hole.

 

Have someone operate the Clutch and measure how far that Bolt Head moves. 0.8 mm is the bare minimum, ideally at least 1.0 mm.

 

This will guide you where to look next.

Was the primary gear rebushed or was it a new primary gear ?

 

[bpirie1000]

I would go with a possible worn selector fork to be honest. Nowt else for it but engine out box off...

On the bright side it is a moke and not exactly moke weather at the moment is it.

Fine winter project for you.

[Sharks]

Check how much movement you have of the Backing Plate.

Was the primary gear rebushed or was it a new primary gear ?
 

Thanks Spider, unfortunately the Wok is already off, about to pull the flywheel.

The primary gear was new from the NZ classic mini mob.

 

 

I would go with a possible worn selector fork to be honest. Nowt else for it but engine out box off...

On the bright side it is a moke and not exactly moke weather at the moment is it.

Fine winter project for you.

Shouldn't be, it's every gear not just 1st/2nd, and that selector fork was absolutely beautiful when this gearbox went in 12 months ago. I haven't measured up a fork and synchro hub with less slop in it before or since.

Also, speak for yourself - Santa drives a rusty Holden Ute and wears a singlet, shorts and thongs down here. This is the third year in a row that the Moke has been out of commission in the summer time. I only seem to get to drive it when I'm freezing and it's pouring rain!

[Spider]

 

Was the primary gear rebushed or was it a new primary gear ?

 

The primary gear was new from the NZ classic mini mob.

 

 

There's been loads of issues with the new type of bushes.
 

[Sharks]

 

There's been loads of issues with the new type of bushes.
 

That would be right. With the state of classic mini suppliers at the minute, there's probably loads of issues with everything from wheel nuts to piston rings. I'd love to be able to buy a part and not have to pull my engine out to replace it again in twelve months.

 

If it is the primary gear bush, the engine does have to come out, doesn't it? With a lot of cursing you could probably get the flywheel housing off in the car, but I doubt you'd get it back on (and sealed) again, would you? You'd need to take the engine out to clean it up and do it properly.

[Spider]

You can get the flywheel off and pull the Primary Gear with the engine in the car.
 

However, whether it can be repaired or not from there you won't know until you get it out. I did get lucky once.

[coopertaz]

no one has mentioned about crankshaft end float check yet. worn out thrust washers will cause drop of revs and clutch issues. can check in car easy enough with dti

[Sharks]

Coopertaz, you might be on to something. Finally got our flywheel puller turned down small enough to fit between the engine and the subframe (usually do this sort of thing with the engine out) so I managed to get the flywheel off this morning.

 

 

I think all looks okay in here, and the primary gear spins nicely, though I do wonder if there is supposed to be a teeny bit of oil lubricating the primary gear bushes?

 

The real trouble is that I have 12 thou between the primary gear and the retaining washers. The book I have says it should only be 3-6 thou. I do recall when this primary gear was fitted that we were on the 6 thou end of that scale (and from memory we had a 118-120 thou washer behind it), but in 20,000kms its gone out a long way. Could this be the cause of my clutch trouble, or an unrelated fault? At any rate, it certainly needs fixing while we're here.

Edited by Sharks, 19 December 2024 - 03:59 AM.

[Lplus]

Coopertaz, you might be on to something. Finally got our flywheel puller turned down small enough to fit between the engine and the subframe (usually do this sort of thing with the engine out) so I managed to get the flywheel off this morning.

 

 

I think all looks okay in here, and the primary gear spins nicely, though I do wonder if there is supposed to be a teeny bit of oil lubricating the primary gear bushes?

 

The real trouble is that I have 12 thou between the primary gear and the retaining washers. The book I have says it should only be 3-6 thou. I do recall when this primary gear was fitted that we were on the 6 thou end of that scale (and from memory we had a 118-120 thou washer behind it), but in 20,000kms its gone out a long way. Could this be the cause of my clutch trouble, or an unrelated fault? At any rate, it certainly needs fixing while we're here.

Somehow I doubt 6 thou would be enough to render the clutch inoperative.  The apparent lack of any lubricant on the splines might though, I put a thin smear of grease on the splines on assembly.  I would expect to see a very small amount of lubrication at the end of the primary gear.  How much play is there between the bush and the crankshaft?  I'm also surprised at the amount of corrosion on the taper.

[Sharks]

Well - it's a bit worse than just the wrong size thrust washer. Spider has informed me that the Silicone Bronze bushes they put in these modern primary gears are the cause for the following.

For a start, there is no lubrication at the end of the primary gear. When we removed the C-washer, we spotted a nice ring of rust on the crank.


Remember - the primary gear spun really nicely - but it took a lot of pulling to get it off the crank. No surprise in hindsight...




Thanks to everyone for your help. Looks like the Moke is going to be off the road for a while.

Edited by Sharks, 19 December 2024 - 08:49 AM.

[Spider]

Bumma mate