Grey motor gearbox tool I’d :7A2

[JohnBM]

Just wondering if anyone would have the shaft 7A2 as shown in GMH manual , they would be willing to sell . I will be wanting one when I do the box up in the Not too distant future . or even the precise dimensions of the shaft to get one made , cheers . John .

[mcl1959]

You just need a shaft from an old gearbox and cut it down to suit. The actual length is not really critical, just a little bit shorter than the reverse idler gear.
I have one here which hasn’t been cut down yet which I saved for that exact purpose.
Ken

[JohnBM]

Thanks Ken, if I can’t get one that someone else has made up already ill look into you suggestion . Cheers . John.

[ardiesse]

John,

Grease is the word your best friend.  You don't really need a 7A2 if you work carefully.  Pack the needle rollers well with grease, and put a thin film of grease on the thrust washers and load them into the gearbox case.  Start the countershaft in the hole just enough to hold the first thrust washer, then gently lower the cluster gear into position.  Push gently on the countershaft, and you'll pick up the gear.  Then it's a case of using a screwdriver blade to align the other thrust washer as you push the countershaft home.

That's the "how", but as usual, I'll ask "why"?  The only reasons I'd rebuild a gearbox are -
The mainshaft bearing is shot (whirring sound on acceleration in top gear from 20 - 40 mph),
Noisy first or second gear,
Chipped teeth (strange clacking noises at the point of disengagement when you shift slowly out of first),
Synchro cone retaining circlips have popped out (no synchro into the affected gear, first and reverse except, obviously).

My dictum is "If it sounds OK, it is OK."  What appears to be wrong with your gearbox?

Rob

[JohnBM]

Thanks very much Rob for your input , I’m thinking more of what’s going to happen down the road , my gearbox is making that familiar noise , you’ll know what I mean , a friend of mine who is very knowledgeable in the grey box has suggested it will be something I will have to address down the road so to speak . So I have procured everything he has suggested over the last 12 months . He mentioned the shaft I was looking for , so was hoping to get one . But he also said like you it can be done being careful using grease . I will do Wangaratta ( from Perth ) the way it is and see how it goes. But I believe to at least be prepared with the parts should the need arises.   I think I told you .that the modified head gasket & the necessary drilling of the block & head have worked a treat with only on avg 1to 2 deg difference between the radiator & head , where as on the Canberra nats run it was more like 8 deg difference. Thanks again Rob , any time I need info I’ll get back to you cheers . John

[ardiesse]

John,

I have a whole playlist of familiar gearbox noises to choose from . . .
What is the noise your gearbox makes, and under what conditions?  First? Second? Third? Reverse? Accelerating? Cruising? Decelerating?

Rob

[JohnBM]

Thanks Rob , the best way to describe it is , when in first gear going up an incline , so under load , it makes a reoccurring noise like if you say the word NOT quickly & repeatedly. Not not Not not not .  If that’s any help , everything else seems ok once up & going , no jumping out of gear or anything . Cheers John

[Harv]

G'day John,

An excerpt from the Crashbox Guide below that may help:

There are quite a few special tools specified in the early Holden Workshop manuals for overhauling grey motor crashboxes. Without a doubt they make the job easier. There is also no doubt that finding the genuine tools is like finding rocking horse poo. Some of the tools can be replaced with common workshop tools, albeit perhaps not in the manner that the tool maker originally intended (think of it as Harv’s School of Tool Abuse). Listed below are the tools identified in the Workshop manuals, and some alternatives.

The rear bearing lock ring must be expanded to allow the bearing to be tapped out of the casing. This can be done with a broad-bladed screwdriver, but a wedge-shaped piece of metal makes the job easier. The original factory tool (tool 7A4) is simply a flat bit of 3.3mm steel with a 36o angle cut in the end. Only the tip (about the first ½”) of the tool is used – the rest is just a glorified handle. The tool can be readily cut from a piece of flat plate. If you are making the press-plate below, use the same 1.3mm steel sheet to make the 7A4 tool. I've got one of these tools (homemade) and am happy to either trace it out for you or loan it to you.

The clutch gear ball bearing is a press-fit onto the clutch gear. To remove it, an arbor press is suggested by the Workshop Manuals. Whilst it is possible to take the clutch gear to your local workshop and have them press the bearing off, it is just as easy to drive it off yourself. To do so, a press plate is required to slip in between the clutch bear and bearing. A 6”x4” scrap of 1.3mm sheet steel with a 1½” slot cut into it does the job nicely. Again, I've got one of these tools (homemade) and am happy to either trace it out for you or loan it to you.

[Harv]

Removing the front propeller shaft housing oil seal from front propeller shaft housing (also known as pulling the oil seal out of the rear of the extension housing) can be a challenge. The seal is an interference fit, and with half a century of vibration, heat, dirt and other abuse, they really don’t like to fall out. It is not very practicable to drive them out by using a drift (or screwdriver) from the opposite end. This is because there is a bronze bushing behind the seal, and the angle of the screwdriver prevents you from getting into the small gap between seal and bushing. A bit of care is also required to ensure that the bushing is not scored whilst driving. You could try levering the seal out with a screwdriver, though this is a long and laborious task. There is also a big risk that when levering on the alloy extension housing lip that you crack a chunk out of the lip. The tool which makes this task easy is the genuine early Holden hubcap remover (see image to the right). The hubcap remover is the right length to slide inside the extension housing, and the claw will engage the small gap between seal and bushing. Supporting the extension housing in a vice, and then gently tapping around the edges of the seal will drive it out squarely. There are probably a few NASCO tool aficionados who have just sworn at me, but I have to admit the hubcap remover makes a very good job of it. For those who want to make their own, a piece of steel rod 10” long with a flattened claw 1” deep will do the trick (no need to make the tool as thick as the original with a 5/8” wide claw). There is a genuine tool to do the job (part 7A9). The tools work by screwing into the rear of the seal, and then using a bolt to push off the mainshaft and remove the seal. I can loan you one of these.

An additional tool which is handy is a main shaft installer. The original tool (7A5) is rare, but can be manufactured from a length of 3/8” threaded rod and some water pipe. Note that it is possible not to use this tool, and to just (gently!) tap the mainshaft through the rear bearing. This is an interference fit, and it too much force is used, you will blow out the cast iron casing… its surprising how little force is needed to do this. I can loan you one of these.

Once the tailshaft is removed from the rear of the gearbox, it will start to leak oil. Gearbox oil is stinky, and is rather unpleasant to take an impromptu bath in. A genuine “stopper” was available (tool 7A1-1 – see images to the right), though are fairly rare. SuperCheap and other retailers sell a universal gearbox stopper to block the hole, though sadly it is not the correct size to fit a grey or red motor gearbox (it does however fit the Aussie 3-speed). One handy tool is a spare tailshaft yoke. The tailshaft yoke will allow you to block the end of the gearbox extension, and prevent the oil from draining out. This can be handy for storing a gearbox full of oil, or for filling the gearbox after overhaul (fill the gearbox whilst it is still out of the vehicle with the spare yoke installed, fit the gearbox then remove the yoke). Another option is to buy a 32mm multi-fit hollow-type kitchen sink plug from Woolworths, and punch out the centre. Whilst not a perfect fit around the main shaft splines, it does a surprisingly good job. Perhaps the easiest option is to drain the gearbox before removing it, and refill it only once installed.

There are quite a few snap rings and circlips inside the gearbox holding various shafts and bearings in place. Most people are familiar with circlips, which have “eyes” at each end and can be pulled out with circlip pliers. Circlip pliers are readily available from places like Repco or SuperCheap. Snap rings do not have “eyes” at the end of them, which means that circlip pliers do not necessarily get a good grip. Whilst it is possible to pull apart a crashbox with circlip pliers, a pair of snapring pliers does a far better job. Snapring pliers are available from engineering houses (places like Blackwoods). Happy to loan you a pair.

Rob and Ken are right, when loading the roller bearings into the counter gear, some grease is used to “glue” the rollers in place. The workshop manuals recommend the 7A2 loading tool (a piece of steel bar) to help the process. The factory tool is too small in diameter, and does more bad than good. A better way to do this is to reuse the old counter gear shaft – it is the perfect diameter, and costs nothing (Rares supplies a replacement shaft in their kits, so no need to buy one).

Cheers,
Harv

[ardiesse]

John,

It sounds to me like you have a chipped tooth on the cluster gear.  I gather the gearbox is quiet when you decelerate in first?  The chip could also be on the first-reverse sliding gear, but in that case, the "not-not-not" sound would be slower.  Also: if the chipped tooth is on the first-reverse sliding gear, then it will make the "not-not-not" sound when you decelerate in reverse. (You have to get going at a decent rate in reverse and then take your foot off the accelerator, leaving the car in reverse, for this.)

You don't need to pull the gearbox apart completely to replace the cluster gear.  The reverse idler gear comes out first, then you can remove the cluster gear, leaving the input shaft, mainshaft and synchro assembly in place.  But if the first-reverse sliding gear has damaged teeth, then a complete tear-down is needed.

Rob

[JohnBM]

Hell ,what do I say . Thanks Rob& Harv for all that info , I have to sit back & take it all in , I have a mate who did his box quite some time ago so will be engaging with him with the information you have both given. Plus your tool loan offers Harv . Very much Appreciated it’s good to know that like minded people are out there to help us less mechanical minded souls .    I might add I’m having a devil of a time getting on to the forum it’s telling me it’s    403  Forbidden I’m getting around it but it’s not secure, I will copy all this info for when I need it . Cheers John

[surferboy]

I would just turn up the volume on the stereo  radio until the noise disappears John 

I did find out that turning up the stereo volume DOES NOT fix a wobbly steering wheel though 

 

[JohnBM]

Having to tow you back across the Nullarbor Graham , would really test my gearbox , radio volume up or not 🤪