Gear selection troubleshooting

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mini_surfari
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Gear selection troubleshooting

Post by mini_surfari »

Evening all,

Need some help from people with clear minds!

Took the engine out of the van over the winter to replace a weeping gaskets, which turned out to be most of them :lol: .

Put it all back together and ran it up etc etc. But finally after a break in the weather took it for a test run. Except you can barely select any of the gears whilst driving, and some times can't get it in at all.

- With the engine off, you can select all gears.
- Sat idling you can select gears if you pump the clutch pedal a few times. (always 3rd and 4th, sticks on 1st and 2nd sometimes).
- Clutch slave was just unbolted and left in the engine bay during the removal.

So this afternoon we

- re-bled the clutch, no air came out at all.
- double checked and adjusted the throw-out
- and also tried installing a longer pushrod into the slave.

The longer pushrod allowed the gears to all be selected whilst running (didn't drive it though as it was raining sideways by that time). However when I measured the travel of the clutch arm it remained the same as with the standard one. Which has stumped me, as I thought oh maybe the slave cylinder is knackered and not giving full travel.

There are no leaks from the slave or master cylinder.

Any suggestions, or am I missing something obvious :oops: .

Cheers, Oli
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Re: Gear selection troubleshooting

Post by Rolandino »

Check that the center main thrusts are ok. Get someone in the car pumping the clutch while you have your hand on the pulley below the rad. If it moves more than 10 thou, that could be your problem. What about the clutch arm and the plunger that holds the release bearing?
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360gts
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Re: Gear selection troubleshooting

Post by 360gts »

Oli,
You need to give us a bit more information.
First, did you have any selection issues last year prior to you removing the engine unit.

Next, how extensive was the gasket replacement?
Was the engine separated from the gearbox/
If not...was the flywheel housing removed....flywheel out etc.

Fitting a longer pushrod will not give more travel....the travel is limited by the two big stop nuts on the throw out bearing shaft.
A longer pushrod is used a lot to compensate for wear in the fulcrum...the pins.....the arm itself.
Let us know what was done for the gasket replacements.
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Re: Gear selection troubleshooting

Post by mini_surfari »

Thanks for the replies so far, will check the pulley travel, and the plunger!

Yeah sorry I should’ve said, gearbox separated from engine block, so clutch and flywheel off. Diff output flanges and speedo drive housing.

No selection issues, or clutch issues before removing the engine. All the flywheel, linkages etc, were marked and went back in he same orientation.

Also it’s a remote selector, rather than magic wand.
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Re: Gear selection troubleshooting

Post by agricola »

I've had problems with old clutch arm bending at the ball end, especially with updated clutch covers. And you dont need much as the mechanical advantage is large. The minispares are supposedly made of better material, so i replace my old ones.
Also check the clutch / flywheel assembly carefully Keith Calver setup instructions are worth reading.
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Re: Gear selection troubleshooting

Post by minibitz »

I guess you can rule out any issue with the selector mechanism as you are able to roll through the gears with the motor switched off.

Next question would be did you check and set the idler gear and primary gear clearances correctly?

The symptoms describe classic clutch drag which is normally caused by poor clutch adjustment or wear in the lever mechanism - lever ball end, plunger, lever clevis pins and eye of slave push rod. Even slight wear in these items adds up to a large loss of travel.

The odd thing is it wasn't doing it before so what has changed?
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Re: Gear selection troubleshooting

Post by 360gts »

Agree with Minibitz...."The odd thing is it wasn't doing it before so what has changed?"
Been scratching my head on this one.

You can select the gears with engine off......(BTW....you don't need the clutch for that)

You can select the gears with engine running but not moving.......You do need the clutch for this.....However, you say you have to pump the pedal a few times.

So, this leads me to think the issue is with the input drive.....
Thinking the primary gear is all gummed up on the crank or, the clutch plate is rusted on the splines.

Couple of additional questions.
When you were test driving....did the gears grind when you were trying to select?
Is this a spring clutch or diaphragm unit?
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Re: Gear selection troubleshooting

Post by mini_surfari »

I think I'll check the clutch arm first as said. As I have overlooked that when reassembling as the wok was left complete.

Yep idler gears checked and set before it went back together.

As you say this is the most frustrating thing. The engine was overhauled, and only went back in the car in 2022, drove and ran perfectly, however I've always used hylomar on gaskets and this engine seemed to weep a abit. So during the winter just whipped it out and replaced most gaskets and used loctite instead (after reading on this forum). I've cured the leaks/ weeps, but now it doesn't go anywhere :lol: .

Its only covered 750 ish miles since running, all the clutch is new, primary gear turned nicely on crank tail when it went back on.

Diaphragm clutch on this one.
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Re: Gear selection troubleshooting

Post by Exminiman »

Did you replace the clutch this time or was it replaced back in 2022 ?

There has been a few issues with pressure plates not machined with the horns (upstands what ever they are called) being wrong lengths or differing lengths…
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Re: Gear selection troubleshooting

Post by mini_surfari »

Back in 2022 sorry the clutch was replaced.
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Re: Gear selection troubleshooting

Post by Exminiman »

Not being funny, but as 360gts said “ the travel is limited by the two big stop nuts on the throw out bearing shaft”

The nuts are not stopping the throw too early are they ?
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Re: Gear selection troubleshooting

Post by agricola »

Ah new clutch plate might be quite a bit thicker than the old one. check the straps pillar set up as per KC
https://www.calverst.com/technical-info ... alignment/
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Re: Gear selection troubleshooting

Post by agricola »

Ps the 15/16 big nuts are there to stop you pushing the clutch too far so if they are set too tight they will stop the clutch working
again KC
https://www.calverst.com/technical-info ... djustment/
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Re: Gear selection troubleshooting

Post by mini_surfari »

Nope, even with them backed all the way off (did this to measure travel) still have the same issue.

Thanks for all the help so far by the way!

I shall read that article now, thank you.
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Re: Gear selection troubleshooting

Post by Andrew1967 »

Did you replace the plunger that the thrust bearing sits on Oli ?

That coupled with potential wear on the arm ball does cause big problems. The usual botch is to bend the arm itself and/or add a longer pushrod.
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Re: Gear selection troubleshooting

Post by Polarsilver »

Agree with "All" the advice given .. also as & when you next take the clutch apart ..check for apparent wear on the Primary Gear Splines & does the Clutch Plate Slide along spline without issues... as suggested buy a MS Clutch Arm & easy eliminate that arm ball end wear issue & despite the fact that you do not need one .. i fit an adjustable Push Rod & then fine tune the Clutch Pedal bite point to suit just me ;)
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Re: Gear selection troubleshooting

Post by Andrew1967 »

Alteratively, Norman is to weld up the ball and file round to get a good fit in the plunger .. whilst checking the hole in the plunger isn't (it more than likely will be) worn. That can be welded up and then filed or drilled out as well if required or replace with new.

I prefer to recondition originals were possible of course :)
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Re: Gear selection troubleshooting

Post by mini_surfari »

Thanks all,

Will start with the clutch arm and plunger and report back.

Just as a side note, has anyone had problems with 'genuine' slave cylinders? I had a similar issue on my other car when a non genuine one was fitted, hence the lengthened clutch arm being available.
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Re: Gear selection troubleshooting

Post by Peter Laidler »

I've had a feeling in my bones that this was a gearbox internal issue. But the consensus, the wisdom of the crowd seems to be the clutch arm or EXTERNAL. Maybe it's time to look at everything externally.

One method to test for worn components is to put a long open ended tube (scaffold pole ?) over the clutch arm and operate it manually. That overrides defective hydraulics, worn axis pins and worn lower balls - if you'll excuse the phrase....-, that cause the dreaded accumulative error.

Wheels off or raise front, run engine. Lever the arm out manually and change gear and.........

If we was closer Olli, we'd have this sorted by tea time
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Re: Gear selection troubleshooting

Post by 360gts »

Peter Laidler wrote: Sun Mar 24, 2024 5:50 pm I've had a feeling in my bones that this was a gearbox internal issue. But the consensus, the wisdom of the crowd seems to be the clutch arm or EXTERNAL. Maybe it's time to look at everything externally.

One method to test for worn components is to put a long open ended tube (scaffold pole ?) over the clutch arm and operate it manually. That overrides defective hydraulics, worn axis pins and worn lower balls - if you'll excuse the phrase....-, that cause the dreaded accumulative error.

Wheels off or raise front, run engine. Lever the arm out manually and change gear and.........

If we was closer Olli, we'd have this sorted by tea time
Hi Peter,
I am not convinced it is the arm...Oli said there was no issue before taking the unit apart. He replaced all the components as they came off. Didn't change the arm or any of the associated parts.

I am leaning more towards clutch drag.....the plate not freeing up to stop the drive to the input shaft.
Remember, according to Oli....it was dismantled for a while....flywheel off....sitting there.
Maybe Oli could tell us if he removed the primary gear during the strip down.
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