question ferret wheel station

[jim fl4]

Hi, I'm keen to understand how these wheel stations work and read that they are removeable as a unit from their respective bevel box. I assume that a shaft with spines locates into its bevel box, is this shaft called the 'inner tracta shaft'?

 

I figure that it is this shaft which slides out when the wheel station is withdrawn? If this is the case, is it an awkward job to line this shaft up when re-fitting wheel station to bevel box?

 

Thanks

 

Jim

[OZITIM]

Yes, and yes. The wheel station is bloody heavy and it is difficult to get it off the workshop floor and up, at a level so that you can mesh together the shafts and at the same time attempt to get the top of the wheel station to fit together so that you can get the 8 hex bolts screwed in. Once together, you have to then screw in the 5 bolts that hold the outer with the inner. You will need to find a person with double jointed fingers that are each approx 10 inches long and a 7/16th spanner. But, the actual meshing bit, is the easy bit. Ihope this makes sense.

[robin craig]

I guess what comes to mind first when I read your post is what exact problem are you trying to correct Jim?

 

There may be simpler ways to execute the task.

 

Robin

[Diana and Jackie]

if you intend to separate the wheel station from the bevel box, the wheel station is >>>VERY VERY heavy!!!<<<< I would recommend using an engine crane to support it whilst you do split the wheel station and bevel box using a sling around the outer hub. As one reader says the set screws holding the two together are problematic. The wheel station is also held in place by the fixing at the top of its suspension arm.

 

Diana

 

Hi, I'm keen to understand how these wheel stations work and read that they are removeable as a unit from their respective bevel box. I assume that a shaft with spines locates into its bevel box, is this shaft called the 'inner tracta shaft'?

 

I figure that it is this shaft which slides out when the wheel station is withdrawn? If this is the case, is it an awkward job to line this shaft up when re-fitting wheel station to bevel box?

 

Thanks

 

Jim

[Starfire]

When I replaced one on the Saracen, we used 3 people and a fork lift. It was a pain in the arse.

 

Cheers,

Terry

[jim fl4]

Blimy :shocked:, I had already figured it had to be very heavy and would have to be suspended and kind-of slid into place.

 

I ask because I assume that when people with such vehicles experience a lack of drive but no wobble etc, then in order to eliminate either the bevel box or drive shafts one would have to disconnect each to ascertain where the problem was. Clearly, first one would be the prop shafts, but then,(if the dowels are secure) that would leave only two other probables?

 

I have read acticles of broken tracta joints on Stollies and assume that these are similar, albeit on a larger scale to a ferrets?

 

Thanks to everyone from all over the world for taking time out to put finger to key :).

 

Cheers

 

Jim

[Diana and Jackie]

The words Highly dangerous come to mind - treat with respect.

 

Diana

 

When I replaced one on the Saracen, we used 3 people and a fork lift. It was a pain in the arse.

 

Cheers,

Terry

[Diana and Jackie]

Jack it up on one side, there should be some backlash in each wheel - a very small amount not a complete wheel turn. This is also a good way to see how well the brakes are adjusted as it possible to maladjust the brakes so that there is no brake action on one wheel. I know as this was how mine was when I bought it - a death trap!

 

Diana

 

 

 

 

Blimy :shocked:, I had already figured it had to be very heavy and would have to be suspended and kind-of slid into place.

 

I ask because I assume that when people with such vehicles experience a lack of drive but no wobble etc, then in order to eliminate either the bevel box or drive shafts one would have to disconnect each to ascertain where the problem was. Clearly, first one would be the prop shafts, but then,(if the dowels are secure) that would leave only two other probables?

 

I have read acticles of broken tracta joints on Stollies and assume that these are similar, albeit on a larger scale to a ferrets?

 

Thanks to everyone from all over the world for taking time out to put finger to key :).

 

Cheers

 

Jim

[Starfire]

If you're not getting drive, you can do some diagnostics before removing wheel stations...

 

1. Jack up one side (other side chocked) and with the transfer case in neutral, handbrake off, you should be able to rotate one wheel and the other should turn. Rotating backwards, should give about 5 degrees of motion before the other wheel starts moving back.
   
2. If that fails, have a look at what the driveshafts are doing (you may need to remove the radio tray, some gearbox covers and the front driveshaft covers). If turning the back wheel doesn't cause the driveshafts to move and the front does, you know the break is at the back, or vice versa.
   
3. If you can identify the problem being at either the front or the back, then removing the outer hub will tell you what condition your planet gears are in; if they look fine, then it's either the bevel box or tracta joints.
   
4. Drop the oil from the suspect bevel box; a dead bevel box will have ugly oil in it.
   
5. Repeat for the other side.
   

 

Cheers,

Terry

[jim fl4]

If you're not getting drive, you can do some diagnostics before removing wheel stations...

 

1. Jack up one side (other side chocked) and with the transfer case in neutral, handbrake off, you should be able to rotate one wheel and the other should turn. Rotating backwards, should give about 5 degrees of motion before the other wheel starts moving back.
   
2. If that fails, have a look at what the driveshafts are doing (you may need to remove the radio tray, some gearbox covers and the front driveshaft covers). If turning the ba
   
3. ck wheel doesn't cause the driveshafts to move and the front does, you know the break is at the back, or vice versa.
   
4. If you can identify the problem being at either the front or the back, then removing the outer hub will tell you what condition your planet gears are in; if they look fine, then it's either the bevel box or tracta joints.
   
5. Drop the oil from the suspect bevel box; a dead bevel box will have ugly oil in it.
   
6. Repeat for the other side.
   

 

Cheers,

Terry[/QU

 

Thanks Terry, that's a great post :-),

 

With ref. to Q 4, removing the outer hub - I expect that the removal of the hub cap, (held by 6 or 8 allan key screws) would allow enough of a view of the planet gears to determine their condition, ie with the ability to spin the hub and look for any mashed teeth .

 

Assuming all was well, is there then any possability to view the tracta joints before electing to remove a wheel station. I wonder, for instance if anyone has experience of shifting the rubber gaiter to have a look??

 

Cheers

 

Jim

[Richard Farrant]

 

Thanks Terry, that's a great post :-),

 

With ref. to Q 4, removing the outer hub - I expect that the removal of the hub cap, (held by 6 or 8 allan key screws) would allow enough of a view of the planet gears to determine their condition, ie with the ability to spin the hub and look for any mashed teeth .

 

Assuming all was well, is there then any possability to view the tracta joints before electing to remove a wheel station. I wonder, for instance if anyone has experience of shifting the rubber gaiter to have a look??

 

Cheers

 

Jim

 

Hi Jim,

You need to look at the Ferret EMER (workshop manual). The removal of gaiter will not show you anything. Once you look at the section drawings of the wheel station you will understand the layout of the drive line.

A wheel station can be removed by one person, with a small engine crane and rope sling. I have done hundreds and not a major issue. If you need to remove the inner tracta housing, a special spring compressor will be needed to lift the upper wishbone clear in order to withdraw it..

 

regards, Richard

[Starfire]

I'm not sure on a Ferret, but on a Saracen, you can't see anything if the Tracta joints without removing the wheel station, with the exception of a hole through which a pin is installed (covered by a bolt). Whether that turns (based on where torque is being out in to the system) would indicate if there is a break on the inner or outer joint, but it'd all have to come out to fix it anyway.

 

You should probably swap steps 4 and 5 too. Dumping oil is easier than removing components.

[jim fl4]

Hi Jim,

You need to look at the Ferret EMER (workshop manual). The removal of gaiter will not show you anything. Once you look at the section drawings of the wheel station you will understand the layout of the drive line.

A wheel station can be removed by one person, with a small engine crane and rope sling. I have done hundreds and not a major issue. If you need to remove the inner tracta housing, a special spring compressor will be needed to lift the upper wishbone clear in order to withdraw it..

 

regards, Richard

arhh! thanks Richard :-) . I have studied various diagrams of wheel stations but was still left wondering how they breakdown. I presume you first remove the wheel guard to allow better access for a hoist?

 

Cheers

 

Jim

[Richard Farrant]

. I presume you first remove the wheel guard to allow better access for a hoist?

 

 

Hi Jim,

You do not disturb the mudguard, work can all be done underneath. The EMER explains it well, but lifting the hub and outer tracta assembly can easily be done on your own, as I said, with a rope and small engine crane.

 

Richard

[Jimland74]

Would these photos help you Jim? I've recently replaced 3 oil seals on the front n/s. I have some more photos which have not yet been uploaded from my camera. If you think they'll be useful, let me know

[jim fl4]

Hi Jimland74,

 

Wow, top man , yep I find photos superior to workshop diagrams so many times, really good to have both.

 

I've read about these hub stations and they frienden the live out of me, with, shims, dowels etc etc. Fair play to you for getting stuck in :-).

 

How long did it take to strip the hub and are there any points to pass on, I'm sure they will be others keen to hear of your experience.

 

Many thanks

 

Jim

[Jimland74]

I had expert help from an ex armoured regiment mate. Invaluable. Had most of it dismantled in a day (5 hours) reassembly took about another 12 man hours. Tips - take lots of photos. Don't lose the needle roller bearings, there's about 28 in each planet gear! When putting the 2 tracta forks back together and fitting the gaiter and gaiter ring, ensure the assembly is horizontal. We initially had it hanging down as it was easier to fit the bolts on the gaiter ring, but when they were tightened up there was little movement in the hub/chrome ball. At first thought we needed more shims, but then realised the cause of the problem. When refitting the needle rollers in the planet gears, put one at the top first, this keeps a nice gap at the bottom where you can then start to easily fit the rest of them.

 

I would never have attempted it on my own!

[jim fl4]

I had expert help from an ex armoured regiment mate. Invaluable. Had most of it dismantled in a day (5 hours) reassembly took about another 12 man hours. Tips - take lots of photos. Don't lose the needle roller bearings, there's about 28 in each planet gear! When putting the 2 tracta forks back together and fitting the gaiter and gaiter ring, ensure the assembly is horizontal. We initially had it hanging down as it was easier to fit the bolts on the gaiter ring, but when they were tightened up there was little movement in the hub/chrome ball. At first thought we needed more shims, but then realised the cause of the problem. When refitting the needle rollers in the planet gears, put one at the top first, this keeps a nice gap at the bottom where you can then start to easily fit the rest of them.

 

I would never have attempted it on my own!

 

Hi Jimland74, Thank you for the update and your tips .

 

Jim

[sexton]

If you need to remove the inner tracta housing, a special spring compressor will be needed to lift the upper wishbone clear in order to withdraw it..

 

regards, Richard

 

We are replacing all the oil seals in a Ferret so had to remove the inner tracta housings. We came up with this spring compressor. It worked well.

 

Malcolm

 

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