Speed up a 969?

[kw573]

Hello all,

I want to report on yesterdays' and todays' progress.

The front assembly is next. I checked over the parts for possible problems and found that the pinion flange nut was not too good on its' thread, so out came the thread file as it is a non-standard thread (approx 1" x 18tpi), for a clean-up. That worked OK.



With no other problems that need to be sorted now, I fitted the new bearing cup to the pinion carrier . . . . . .



. . . . and cone/race/rollers to the pinion. This was a slow process, and tiring.



Next was to set the pinion bearing pre-load which is simply tightening the pinion nut (which doubles as the seal surface!) and feel the resistance to turning.
Then all that again with the crownwheel shaft, which also carries the spur pinion for the second ratio reduction. This shaft is held at each end with a large-ish bearing, each of which had to be driven home the same way as for the pinion bearings. Then assemble it in the housing with its' shims to check/adjust preload. Strangely, it was locked up tight with a couple of mm left to go. Hmmm . . . In frustration, I called it a day.

Next morning, when a lot fresher, I checked it and everything looked right. So kept looking, dis-assembling the shaft and bearings only to find the neither of the bearing cups were driven properly home. Ooops. That fixed, I set it up again only to find that I needed a shim that I didn't have. So I made one from some .010" sheet steel the neighbour had.



This also gave me the chance to use the step drill I purchased after advice from you guys after my previous attempts.
Worked like a beauty!!



The next step was an initial setting of the backlash (free play between the crownwheel and the pinion). The book says .005" - .010". I much prefer the less the better, so aimed for .005".



Then it was attending to the "setting" of the crownwheel and pinion. I think I mentioned this a bit when doing the rear diffs. Anyway, this diff was not going to be co-operative. And after pulling the bearing carriers about 12 times, I managed the contact pattern shown below. Good height, but a bit narrow and quite toe-y. It was becoming a case of diminishing returns, with only very very little change in the last two shim adjustments. That'll do. It's the front diff and won't be used much.



Yes, last time I used "bearing blue", but as I didn't have any this time, I just used some enamel paint. Works fine.
Wow. I was not looking forward to setting up that diff, sure am glad it's done.

Have a nice day,
Sam

[kw573]

Hi,

Well, I managed to get back to the front diff today. Assembled the diff carrier after cleaning it, fitted bearings and bolted it into the diff housing. Tidied up a few loose ends (lock washers, thread-tape bungs, etc) and now only need to re-co the pinion seal surface and it is finished. This I will do by skimming it in a lathe.

So, out came the axle housing for a check over, cleaned the inside where the diff goes, found the nuts/washers for the CV housings but forgot to check for the nuts for the diff!!! Fitted the seals at the ends where the CV housings bolt on.



And that was it today.
Sam.

[kw573]

. . . . continued.

A mate has a lathe suitable for mid-sized work, so I went there and skimmed the seal surface on the pinion nut. For the machinist, I didn't have a suitable mandrel, so just held it in a 3 jaw chuck and skimmed most of it, then reversed it to finish. Not as accurate as I'd hoped, but will certainly work. As a precaution, I shortened the spring in the seal slightly for a bit better pressure in the lip. I have always found pinion nuts to be among the tightest on a vehicle. Yet this design would have them tightened with a Y spanner on 1/4" pins!



Once all assembled, it was dropped into the axle housing.



Then laid it over on axle stands. The CV housings were fitted the other day. Unfortunately it is all too heavy for manhandling now, all chains and gantrys.



A start was made on the brake drums. I expected to be sending them off to be machined, but after cleaning up the first one, it is pretty good. Haven't started on the second one yet. Although it seems like a lot of work, I am splitting the hub from the drum. This makes a proper clean much easier. There was light rust between the mating surfaces. The nuts on the back of the wheel studs are very tight, so to hold the hub I just drop it on a wheel.



Today I sent the wheels for the front to the local tyre shop for dis-assembly.

So far, so good.

[fwd1943]

hey sambo looking good! your the man ,the wrecker will be in a world of its own , bloody great job lol [

[kw573]

Thanks Dennis.

It is a wet Sunday here.

I finished the front hub assemblies the other day. Check out the bent stud, howd they manage that?



Fortunately, the drums did not need machining, compliments of the grease retaining felt, which lets wheel bearing grease out onto the drum in neglected vehicles, lubricating the brakes. Great for wear, but not for stopping! The M1A1 was the same.
Ready for assembly:-



The studs are a medium drive fit (firm hits with a good size hammer) and have flats that go in a groove in the hub to stop rotation.



Although the left-side wheel studs are left-hand thread, all the inside nuts are right-hand threaded. They are then peined slightly on the end.



To be continued . . . . .

[kw573]

. . . continued.


When I took the springs off the axle housing, I found this, a broken and very firmly stuck spring centre bolt head.



As well as holding the spring pack together for assembly, the centre bolt also keeps the axle from sliding forward or backward on the spring. This can dramatically affect wheel alignment amongst other things.

After some hammering and chiseling, I tried to drill it out.



Although that worked, it still needed some real hammer and chisel work.



Another issue I had to decide on what to do was significant pitting on the seal surfaces for the front axle shafts.



At first I was going to weld and machine them, but local people more knowledgeable than myself said that would probably set up stress points in the metal, leading to failure some time in the future. So it was back to fitting a sleeve. After finding a suitable piece of stainless steel tube, I trimmed it up and turned the axle to suit. The sleeve is an interference fit of about .007".



When warmed up, the sleeve dropped straight on without and problem.



Then return to the lathe to remove any burrs, and for a bit of a polish and all done.

. . . . continued.

[kw573]

. . . continued.

As I am hoping to have the front axle assembly fitted in the next week or so, I thought that it might be a good idea to check out the steering box so I can fit it and so steer the rolling chassis around the yard when required. So here is the steering box as removed from the chassis. That's the chassis bracket behind it.



Didn't look too bad. But when I took the cover off it was a different matter. No oil, just a lining of watery sludge. Hmmm. . .



So I dis -assembled the whole thing. As with every other gear case I've been into on this truck, all the bearings were very stuffed. I'm beginning to wonder if someone took this truck for a real deep swim at some stage, and didn't do any maintenance afterwards?!? An interesting bearing in it is the sector pin bearing. It is an 09195-DB. The 09195 is a fairly common bearing. But the "DB" is a double (back to back) outer (cup). Anyway, after making some enquiries, they are not available in Australia, and bearing suppliers want over 10 times the price of a single. Anyone got any? Fortunately, I have 1 1/2wrecks, one of which yielded a fairly good set of bearings and worm.

Here are the main parts cleaned and painted. The double bearing cup can be seen in the foreground.



The tube sticking out the main housing is for the horn wire. It is sealed at the bottom to stop oil leaks and is long enough to rise well above the oil level. A pretty good idea really.

Have a nice day.
Sam.

[kw573]

. . . from a related post on "Effects of tyre size . . ":-

"As for a reversed extra transmission, this was suggested on "Speed up a 969" a long while ago. Sgt. Hancock kindly suggested a "brownie box", a three speed joey box. Perfect! Except, there is not enough room in the chassis. Combine a short wheelbase, transfercase, (and "remote" at that) and hand brake and that leaves barely 3' (1000mm) of rear tailshaft to play with."

So, my current thinking is to put it all together original (except engine) and see how it goes. Then play with tyre sizes during the running in of the new truck. Another real possibility is to have a set of higher OD gears made for the gearbox, say from 0.78:1 down to 0.68:1. If there is space in the case. It is a huge, and therefore presumably very strong box.

I still have no idea what the front rims are on the period pics of 969s on singles. A long while back, Jeff Jensen suggested "The front wheel looks very familiar like on a 5 ton 6x6 and it is off set to be inline with the rear." They may do. Can anyone inform me on these rims? M series trucks are thin on the ground down-under.

Thanks,
Sam.

[gerrykan]

Sam,
Are we to assume that you want to stay with a NDT or NDCC type of tread on the tires?

[kw573]

hi,
I don't want to wear my ND/NDCCs out on long trips of bitumen, so am hoping to have two sets:- one set of ND/NDCCs for short trips and shows and one set of new lug type or similar to fit for a long trip. As there are very few M series vehicles downunder, usable ND/NDCCs in 20" are a bit thin on the ground. From time to time someone imports a bunch and I have been buying them bit by bit over the years as I can afford it.

I had a revelation today from a bloke I used to teach metalwork to. We were talking about changing ratios for higher/lower speed. He had fitted a set of replacement gears into his Suzuki 4WD for rockclimbing, changing both low range and high range ratios. I don't understand how it could change high range without altering the distance between the three shafts. But it did. Well, as the basic design of that transfercase and the 969 transfercase is the same, there may be an option to speed up the 969 in the transfercase. My error in thinking was, apparently, tying ratios to gear diameter rather than circumference (or that centre height of the teeth, whatever that is called. Anyone?) Time to do some more sniffing around. Can anyone explain what I'm talking about?

Have a nice day.
Sam.

[kw573]

Hi,

I found these pictures yesterday. Forgot that I had them.

These are the original pics of the truck that I am rebuilding now, that I took when I first found it.
It was at a mechanics shop in a small coastal town in northern NSW, after suffering a major engine failure of some sort with no. 6 piston. The owner, a house removalist, had said sell it to pay its' bill. So I bought it.





The way I found it was a fluke! I had bought, but not yet collected an M20 Diamond T literally just around the corner, but well out of sight of this 969. It was owned by a completely different house removalist! After several months, I was told of a Diamond T in the town that was for sale by a house removalist. Of course, I thought that the previous M20 owner was trying to re-sell my truck out from under my nose . But when I contacted him, he told me about this 969. Why he didn't mention it earlier, I don't know!?!
So I had found 2 WW2 Diamond Ts, both owned by house removalists, both for sale, at the same time, in the same small town! You never know what is just around the corner !
Have a nice day.
Sam

[Shane Hodby]

Hi Sam
Go to your other thread as I posted a reply on it last night after doing some thinking
Cheers
Shane

[kw573]

Thanks for that Shane, I briefly thought of finding a whole different rear-end of higher ratio, however it is 6x6, not 6x4 and I want to retain a useable front drive.


CV joint dis-assembled, the parts washed and inspected. Wait, did I just say "dis-assembled?" More like wrestled with trying to work out how to get the darn cage, spider and balls out. "When all else fails, read the directions!" So I did. The manual showed an opposite pair of square holes in the cage that allows the spider to be fed out of the housing and cage. I couldn't see it under all the grease. I have seen a thick layer of grease prevent dis-assembly before. One CV joint was good, the other had quite rusted balls.



They are 1 15/64" diameter. I couldn't find any, so pulled a CV joint from a spare axle and it was OK. So I used it. This is re-assembly with all parts, crevices, holes, etc completely packed with grease.



Just when I though I had finished with all the grease, I realized that I had not yet tie-wired the screws in place.



Is that enough for now? Bit by small bit, I am getting closer to putting the front axle into the chassis. I'm looking forward to that.

Have a nice day.
Sam.

[Shane Hodby]

Hi Sam
Mate if you put another rear end in it it will still be 6x6 as your front axle drives off the front of the transfer case infact you may actually run 2 less tailshafts but it would still be a 6x6 are you going to Toowoomba swap meet on Saturday if so give me a call as I hope to be there as well and I will explain how it works
0408 546 244
Cheers
Shane

[kw573]

Hi Shane,
Yeah, I got that fine. The problem would be different ratios at the front wheels in relation to the rear wheels. But, for sure, I may have overlooked something.
Yes, I plan to be at Toowoomba Swap Saturday AM. Try my mobile, if there is good signal at the site.
See you then.
Sam.