EJ gearbox overhaul

Includes clutch, transmission, propeller shaft,
universal joints, differential and rear axle.

Moderators: reidy, Blacky

ardiesse
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Joined: Thu Jan 19, 2017 9:57 am
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Location: Sydney

Re: EJ gearbox overhaul

Post by ardiesse »

It'll be shaft misalignment. The mainshaft components have a left-hand thread (so to speak), therefore engine torque will drive the synchro hub rearwards when in top gear, causing jump-out. Shaft misalignment aggravates the tendency.

It's time to measure up the bellhousing, and get faces machined flat as needed. And, measure the diameter of the bearing bore in the bellhousing to check it's not worn - actually, it's easier just to check the bearing's fit in the bellhousing.

The bearing bores in the case are 2.4375 (= 2-7/16") nominal diameter, if that helps in getting a mandrel made up to check run-out. Except that the bellhousing bore for the throwout bearing slide is a smaller diameter than the outer race of the bearing. There goes that idea.

Rob

(I am thinking here that it would almost be less effort to retro-fit an FX-EK gearbox. You'd only have to change over the exhaust pipe hanger, clutch plumbing, speedo cable, gearshift linkages, engine mounts and driveshaft.)
EJVince
Posts: 84
Joined: Wed Dec 22, 2021 12:14 pm
State: NSW

Re: EJ gearbox overhaul

Post by EJVince »

I think you are right Rob, especially since this all started when I got somebody to work on the clutch in Wodonga, and they said my flywheel and bellhousing were no good so they changed them. Of course it was easy for them to just blame the gearbox even though I didn't have the gear jump out before they worked on it.

Will think about what I do next weekend, certainly taking gearbox off for a good look at it, might try the one on bench to see if that does the same thing but still not totally confident about the front sychro cone on that one, what the heck though doesn't take long to switch a gearbox over. Bit more time consuming to take bellhousing off.
EJVince
Posts: 84
Joined: Wed Dec 22, 2021 12:14 pm
State: NSW

Re: EJ gearbox overhaul

Post by EJVince »

So I was going to try just changing the gearboxes this week, and see if that made a difference with existing bellhousing. Although planned to have a closer look while gearbox was off before deciding.

When I went to take gearbox off it certainly didn't come out easy like it usually does, it seemed to be stuck on splines, and I was real careful supporting it throughout so I sure didn't let it hang, eventually got it off.

Tried drive shaft yoke in extension housing, and was wuite loose in bushing compared to spare gearbox which was a snug fit.

Tried input shaft in a new pilot bearing, and was looser than input shaft on spare box, which was a nice fit.

Ran through gears, and with the new side cover I made up I could see when taking cover off it was fully engaged in third, double checked side cover and locking ball was firmly engaged, and really takes positive force to push it out of third so nothing wrong with that at all.

Tempting to put spare box on car, but I still don't trust front syncro on that, gears in existing gearbox look great and I know mainshaft is new old stock recently. My though is use existing box, but swap input shaft and extension housing from box on bench.

However still concerned when I try puting input shaft on by itself with exiting bellhousing and clutch parts that it sometimes sticks, you rotate it and better fit on some splines than others.

Also, still concerned the existing bellhousing that mechanic put on just before trouble started isn't great, and noticed fine cracks near both mounts, not sure if they currently effect integrity or not, see pictures.

Anyone want to offer comments, decided to stop as feeling pretty stuffed after the days work, and concentration was starting to go.

Thinking of doing as above with gearboxes, but change the bellhousing over, as one on bench that came with gearbox looks in really good condition. The sticking on splines is making me wonder if either damaged the clutch splines while working on it, but the clutch was working fine with no noises or clashing changing gears, it's not done many km's so maybe thats still fine, I could pull it off and have a closer look at the splines.
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ardiesse
Posts: 1074
Joined: Thu Jan 19, 2017 9:57 am
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Location: Sydney

Re: EJ gearbox overhaul

Post by ardiesse »

Vince,

When a job becomes a chore, walk away and come back next morning . . .

I'm not familiar with the rear engine mounts on an EJ, but the lines on the bellhousing where the clutch cover fits are scratches, not cracks. And the parallel lines on the mount bracket aren't cracks either - they're the marks where sharp edges on the press dies took some metal off the bracket as it was being made.

If you have a digital caliper, why not measure the diameter of the spigot on each input shaft? You might be surprised how little they differ.

The input shaft sticking on the clutch splines is a problem worth getting right. It won't affect gear jump-out, but it will make the clutch plate tend to drag a little, crunch into first and reverse, and lead to balky or crunchy gearshifts into second or top. At this point it will be easier in the long run to remove the clutch and test-fit it in all positions on the input shaft.

(EJ. The shop manual says to remove the clutch fork assist spring and remove the clutch fork. Yeesh. That's a world of pain. It's less trouble to take the bellhousing off the motor.)

Clean the splines on the hub with a toothbrush and WD-40/degreaser/kero/turps first. If there's rust powder or stains on the splines, put a little rust converter on the splines (both input shaft and clutch plate), then wipe clean and WD-40. The clutch plate should be a free sliding fit on the input shaft, and the hub shouldn't wobble on the shaft. If the clutch disc wobbles on the hub or has backlash, bin the clutch plate and buy a new one.

Now that the bellhousing's off, get it (them) measured and trued up as necessary.

Rob
EJVince
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Re: EJ gearbox overhaul

Post by EJVince »

Yes, I agree at times you have to walk away, thanks for the reply Rob.

Yes, I showed a mate of mine the pictures at the club tonight, he said same as you just scratches, and I agree looking at them again.

I actually bought a digital caliper the other day so might as well put that to use, probably isn't much difference in the input shafts.

Think I will likely just get a new clutch plate, for what they cost, that way I can make sure I don't have to do this job for a while, just means I will leave the car out of action till next weekend but that's okay, determined to get this job finished for once and for all. Plus I could take the spare bellhousing and get it measured somewhere during the week too, and have that ready to just swap over and later fix the other up as a spare.
EJVince
Posts: 84
Joined: Wed Dec 22, 2021 12:14 pm
State: NSW

Re: EJ gearbox overhaul

Post by EJVince »

Just been checking out the 2 input shafts, yes you are right Rob with callipers both are pretty close to exactly 15mm where they fit in the spigot bushing.

The one from the gearbox that has been on the car, which isn't original as I put it on anout 15 years ago is different from the original EJ input shaft in a couple of ways, it has what I think a breather hole on the outside, and inside a hole beneath the roller bearings. Splines and tip ptetty sure are the same. I did notice looking closely the teeth that engage with the hub seem about 2mm longer, quite noticeable in the photo. This one on the car just says Holden S9 with no part number, does that mean anything to anyone?

So all the same it worked with no issues for years, but still makes me wonder if in long term it is causing some grief, especially since I got someone to overhaul clutch then someone else overhauled gearbox about 4 years ago which is when trouble really started. Still thinking of putting the original EJ input shaft on to play it safe.

I checked for a part number on the cluster gear I put in about 15 years ago, and looks identical to the EJ one except some marks like little notches which I think they put on later replacements. Part number is 7423270 M4, does that mean anything to anyone? This I think will work just fine if I keep it.
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ardiesse
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Joined: Thu Jan 19, 2017 9:57 am
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Re: EJ gearbox overhaul

Post by ardiesse »

Vince,

You have one early and one late input shaft. Go back through the "Accelerator" references. Found it. April '64. The EH and later input shafts were drilled for a ventilation hole. But I think your input shaft is HD or later, on account of the dimensioning of the synchroniser teeth.

7423270 is the EH cluster gear.

Your gearbox won't work properly with an EJ synchro hub and late input shaft. You will have to use the input shaft with no ventilation hole. Or you'd have to rebuild the gearbox with HR synchro hub and second gear, which would then force you to use a "collarless" 1st-reverse gear, and HR shifter yokes. That would get out of hand.

The disadvantage of the early hardware is the risk of chewing up the top gear synchro cone. Make sure the Belleville washer doesn't break, and pay particular attention to the location of the input shaft. Refer to the August 1963 "Accelerator".

Rob
EJVince
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Re: EJ gearbox overhaul

Post by EJVince »

Totally agree Rob, I will switch to the earlier input shaft, amazes me I got away with running the late one for so many years with an original EJ hub, wonder if its damaged the hub, at the risk of having to pull off the box I think I might try it as the other hub isn't perfect, I think it fits sort of but doesn't fully engage so might not have damaged the internal splines. Repco and Super Cheap Auto aren't much use for shims around here, might have to make some maybe?

That cluster gear I have seen advertised on Ebay as suitable for EJ and early EH, but they might be wrong.
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ardiesse
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Re: EJ gearbox overhaul

Post by ardiesse »

That's the one . . .

The special shims would be like rocking horse poo. You'd have to get a machine shop to make one up in the exact thickness you need. But if you use a late EJ bellhousing, this won't be a problem. Measure the depth of the counterbore in both bellhousings. That'll inform your choice.
EJVince
Posts: 84
Joined: Wed Dec 22, 2021 12:14 pm
State: NSW

Re: EJ gearbox overhaul

Post by EJVince »

Glad I fiddled around in the garage after work now, was going to leave it till the weekend, thanks Rob 👌

Rocking horse poo, gave me a laugh, I felt sure you would say coke cans will do 🤣🤣🤣
EJVince
Posts: 84
Joined: Wed Dec 22, 2021 12:14 pm
State: NSW

Re: EJ gearbox overhaul

Post by EJVince »

I think I would have to order a a shim over phone or internet, nowhere in Bega Valley I think. Are the dimensions other than thickness specified anywhere, or would you just measure bore with callipers?
ardiesse
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Joined: Thu Jan 19, 2017 9:57 am
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Re: EJ gearbox overhaul

Post by ardiesse »

The shim would be a ring of rectangular cross-section. I'm guessing its outside diameter would be the inside diameter of the counterbore in the bellhousing, minus clearance. Its inside diameter would be the outside diameter of the input shaft bearing, plus clearance. And its thickness would be the dimension you measure from the procedure outlined in "Accelerator". A machine shop would have to turn one up from steel tube.

Thinks: 2-7/16" ID to maybe 2-5/8" OD. There's a chance that a small engine oil scraper piston ring would do the job. But you get no control over the thickness.

Or, you get the rear face of the bellhousing machined down by the dimension you measure (depth of counterbore minus thickness of retaining ring plus 0.002").

Rob
EJVince
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State: NSW

Re: EJ gearbox overhaul

Post by EJVince »

Thanks Rob, really appreciate that info. Dennis from Repco Bega is a legend, he said fimac engineering in Bega could probably do those shims, but he is going to make a phonecall as when I gave him the part number he said he might know someone with original shims.
EJVince
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Joined: Wed Dec 22, 2021 12:14 pm
State: NSW

Re: EJ gearbox overhaul

Post by EJVince »

Countershaft bore is between 26-27/32 (0.081-0.084) on both bellhousings, and being that I really don't trust the one on the car as that's when my troubles started, I'm just going to put the other one on as the guy who sold it to me said his dads car was going fine when it came off and he put an auto on. Fimac really weren't interested in making 1 or a few shims for me, and said I should buy some shim stock and cut one or two out since they are pretty thin and they don't carry thin shim material generally. Repco have a pack of Champion shim stock with various thickness, so I might give it a go cutting something out, although it isn't as deep as I thought it might be so in 2 minds as to whether to run with it as is. Was looking at some bearing circlips, and even wondered if you could cut one a little to reduce diameter to right diameter but probably to thick and not quite as wide.

Cleaned up lever and ball assembly, and put new bearing and spring on, remember about 15 years back doing this with housing on car, and remember cussing and swearing for ages till I got the spring on lying under the car. Really didn't take long doing it on the bench.
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EJVince
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Re: EJ gearbox overhaul

Post by EJVince »

Rob you may be able to answer this as I am a little unsure on this point , so where I have put this cork ring, is this where the steel shim would sit in the counter bore? I am just trying to get this clear in my head of how it effects everything, this would mean it would be sandwiched in by the bearing guide?

The check in accelerator magazine confuses me a bit, but if I understand it right, this is where you need to have .002 clearance on the outside rear face of clutch housing. I assume you put the input shaft in with the bearing guide and belleview washer in place, if so certainly not excess clearance as you see from photo, you would only gain clearance if you left the bellview washer off as in the other photo.

Based on this, it really doesn't look like it needs any shimming really, does that make sense?

Or do I measure the clearance without belleview washer in, and sit shim in the top lip under the bearing retainer instead?
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