spacer specs for Minitruck / 60 series disc conversion (1 Viewer)

[chocolatelustboy]

Gidday all.

In the process of fitting some 60 series front disk brakes to my 1972 FJ40.

I've managed to score a set of mini-truck inner-axles and birfields.

While replacing the birfields (one was cracked) the shop has explained that the 'direct replacement' they have for the Mini-truck birfield protrudes from the hub by about 5mm.

They've suggested that there should be a brass(?) washer / spacer that sits on the birfield shaft and is pressed between the hub and the CV joint.

Does this make sense?

if so - anybody know the specs of that 'brass washer' (i.e. size, hold diameter, material, etc., ... in case I need one made up).

Cheers.

 

[edwjmcgrath]

I'm going to guess that maybe the birf they got is not from a 60, mini truck, or post 79 40.
Outside of the US, from 76-79, 40's still had drum brakes but used fine splined birfs that are a few (9?) mm longer than these other disk brake birfs. They are meant to be paired up with longer hubs.

If this new "direct replacement" is longer than the one that they are replacing, I'll bet that's what happened.
If that's the case, you want to go find the correct birf.

 

[chocolatelustboy]

Ahhhhhh ... yes, that would make sense - the 'direct replacement' was both fine-spline and did look to be slightly longer than the mini-truck birfields.

So I need to tell them to source the right part?

They're also waiting for a price on a chromoly birfield from Australia so I'll call them tomorrow and make sure it's the right one!

From what I can gather, I need either a pre 1985 Mini-Truck birfield or a 60 Series - any particular year for that 60 Series?


Interestingly, when I tried the 'tube' trick to remove the inner axle from the birfield, that didn't work: not a hope in hell! And the copper mallet hasn't worked either.
These guys are Automotive DriveLine specialists and reckon that any forcing will likely wreck the end of the inner-axle splines that mate with the birfield. So they've suggesting that they simply cut of the old birfield

Does that make sense or am I just talking to the wrong people?

 

[edwjmcgrath]

You have a choice on the birfs. It depends on what you have for hubs.
The long body hubs that came on your 72 will work with this 76-79 drum brake 40 birf. And you won't have to grind away your axle housing to get it to fit. But you'll have to find another one of these birfs to make a pair. BUT if you ever break one, you'll find that they are rare and hard to find.
OR
You can tell them to go find the correct birf-pre 85 mini truck, any year 60, post 79 40. You'll need to match these birfs up with shorter body hubs from these same vehicles. And since these birfs are a little bigger in diameter, you'll need to do some grinding to get them to fit in the axle housing. Do they know that they are going to have to do this?

If the tube trick didn't work, you're not doing it hard enough. It sounds like they are not really familiar with this vehicle. This disk conversion is not that difficult mechanically, but there are a lot of tricks and confusing options on axles and hubs and the like.

 

[chocolatelustboy]

Thanks Ed.

I bought the disk-brake hubs 2nd hand from a chap who had them previously on his FJ40. He assured me they're from an FJ60.

So I guess my next questions are:

1/ are there any differences between varying years of 60 series hubs that I need to be aware of to get the right birfs?

2/ are there any identifying marks / numbers on the disk-hubs that I could check to confirm the exact model I have?

Re. the tube trick ... we tried pretty hard. Same with the copper mallet. After the novelty of venting some frustration had worn off ... I started to get more frustrated when the bloody things wouldn't come off!!

 

[edwjmcgrath]

There are two basic types of hubs-short and long. You have long bodies on your drum brakes. If the 60 hubs are shorter then you should have the right ones. If they were later installed on a 40 then you are almost certainly fine. Here's a pic.

Short birf/axle is a little shorter and a little larger in diameter. I don't know about any other identifying features.

Re tube trick. I don't know what to tell you. The tube trick is the way that everyone else in the world gets 'em off. Bang it harder.

 

[fjfodee]

Maybe I missed something, but how are mini truck axles gonna work in a 40 housing?

 

[Fast Eddy]

They're also waiting for a price on a chromoly birfield from Australia so I'll call them tomorrow and make sure it's the right one!

Very likely to be the right ones. No one in the US makes a long birf in Chromo. If you want chromo, you need to change your hubs to the short ones.

Bobby long makes chromo hub gears for the Aisin hubs. You might want to think about getting a pair of them if you're going to run big tires. Once you upgrade the birfs, the hub gears will be the next thing to give and it will destroy the splines on the birf when it happens. They're small so shipping should not be prohibitively expensive.

 

[edwjmcgrath]

Maybe I missed something, but how are mini truck axles gonna work in a 40 housing?

What's the problem?

 

[Fast Eddy]

What's the problem?

Mini truck inner axles are different. The long side is the same as an fj60 long side and the short side is unique to the mini truck.

Cruiser Outfitters Tech: Axles

 

[edwjmcgrath]

We're talking the birf/stub axle here. These pics. That's what he needs to get right.
I didn't notice that the original post mentioned that he got mini truck inners too.

 

[chocolatelustboy]

ok, so to clarify, I have a set of:

- 60 series disk-brake hubs (whole wheel including disk and calliper)
- Mini Truck inner-axles attached to fine-spline birfields from a scrapyard

My understanding is that I need to remove the birfields from the Mini-Truck inner axles and then fit them to the 40 series inner axles.

The problem is that:

1/ I can't get the bloody birfields off the Mini-Truck inner axles
2/ noticing that the 'direct replacement' seemed longer than the Mini-Truck birf, the shop took off the outer-casing of the 60 wheel to see if their 'direct replacement' was fitting correctly. This is when they suggested that there should be a brash washer / spacer between the hub and the CV joint. Presumably they thought this would accommodate for any space caused by the longer birfield.


And just out of interest: I expected to need to grind the knuckle top and bottom to make way for the birf. But nope - with a little shove it squeezes in fine. And comes back out with a wiggle and no use of hammers or force. Just mention it in case it turns out that my 40 series axles isn't actually a 40 series axle!

Does that make sense?

 

[edwjmcgrath]

Your understanding is correct.
Do you have photos of your short and long birfs? Is the long birf the same diameter as the short one?

 

[chocolatelustboy]

they're all with the Automotive DriveLine guys so I'll swing by tomorrow and snap some photos.

 

[chocolatelustboy]

ok - been a hectic couple of days with work but managed to swing by the driveline guys - here are some pics showing where the guys reckon the bronze / brass washer is supposed to go.

The guy seems to think that the washer should be the same shape as the inner of the hub - in which case I'm guessing it'll need to be a specially machined piece that fits with those eliptical grooves so that it turns with the rest of the hub?

 

[chocolatelustboy]

these pics show the size - is the slight difference significant / human error? Could just be my shaky hands! Both physically fit into the hub.

 

[chocolatelustboy]

So I measured the shaft on the "direct replacement" - it's 188 mm / 7.4 inches - is that the right length?

 

[chocolatelustboy]

and I think I def have the short hub

 

[Leaping Deer]

ok - been a hectic couple of days with work but managed to swing by the driveline guys - here are some pics showing where the guys reckon the bronze / brass washer is supposed to go.

The guy seems to think that the washer should be the same shape as the inner of the hub - in which case I'm guessing it'll need to be a specially machined piece that fits with those eliptical grooves so that it turns with the rest of the hub?

What you have circled there is the brass/bronse bushing. There shouldn't anything additioal there. Its pressed into the back of the spindle of the hub.

Are you using all parts from the 60 series including the spindle, hub, and locking hub? if so a mini truck birf should be the same.

Were you able to get the birf off the axle. I have had good luck with using the pipe method. I tried doing it on black top or on wood but it didn't seem to work so well I think you really need to slam it on concrete to get it to work well or metal. I just stuffed a rag into the bottom of the tube to keep from damaging the axle. Hammering in a vice never worked well for me.

 

[chocolatelustboy]

yes - the whole of the hub is from a 60 series.

Will try the mini-truck birf again with the hub end fitted (the guys at the shop did this without me being there so I didn't actually see what was the problem).