25 replies to this topic

[lildeucecoop72]

What these variations suggest to me from experience is that at some point, the Idler Gear Bearing has been replaced by heating the case and / or the Flywheel Housing is not aligned to the Gearbox.

Can you kindly through up some photos of the shafts of the Idler Gear ?

Thanks Spider.
I forgot to say above that I am just turning the thrust washer. Everything else was stationary under testing.
Heat has been applied to the transfer case in its time, but checked with another transfer case that I am pretty sure hasn’t been heated, and with the same result, though will double check this.

I’ll pop over to the garage later, and take a few snaps of the orig idler gear that got pitted, the new idler gear, and a spare I have, ( which belongs to another box, that I used for testing). Its the new one that was used in the last test and the one i plan to use.

Edited by lildeucecoop72, 15 May 2023 - 11:38 AM.

[lildeucecoop72]

@Spider as requested

L-R

Orig idler with pitting on transfer case end shaft
New idler intended for use
Spare idler from another box.


 IMG_2312.jpeg   72.07K   3 downloads
 IMG_2311.jpeg   72.93K   3 downloads

I have done another test, (test 6) same as last test but only changing out the transfer case for another one I don’t think has been heatedIt’s possible the starting position of the thrust washer is different in this test.

 

The results are basically the same though the end float gap is bigger. Left side has a larger gap than the right, though a slight improvement...



0 deg
Left feeler 0.009”
Right feeler 0.0065”

Difference between: 0.0025"
Average between: 0.00775”

90 deg
Left 0.0085”
Right 0.006"

Difference between: 0.0025"

Average between: 0.00725”

 

180 deg
Left 0.0085”
Right 0.007”

Difference between: 0.0015"

Average between: 0.00775”

 

270 deg
Left 0.0085”
Right 0.0065”

Difference: 0.0025"

Average between: 0.0075”

 

Average difference: 0.00225" or round to 0.0023
Total average between: 0.0075625” Or to round up, 0.0076”

 

If we just look at the results on the average difference between the gaps, ignoring the bigger overall endfloat gap for the time being, (I can probably address this with a different thrust washer). This shows a slight improvement.

 

Orig transfer case  in 'test 5' (that has been heated to remove bearings in the past): 0.0034"

The spare transfer case  in this test (I believe has not had heat treatment): 0.0023"

Edited by lildeucecoop72, 16 May 2023 - 05:33 AM.

[Spider]

I can see from your old Idler Gear, something's out of alignment !

I'd say from your measurements, your flywheel housing is distorted, as I suggested earlier.

You can make your best guess here what thrust etc to run with, but before long, you'll likely be back in here facing the same issues.

[Steve220]

I had the transfer and gearbox cases trued recently. Surprised how much they are out from factory

https://imgur.com/a/iv8pxBN

[lildeucecoop72]

Thanks Spider, yes that could well be. A few have said that a small amount of difference either side is ‘acceptable’ but it depends on the driving type etc. I would like to get it right though. I would rather avoid the whole process again!

If youre thinking of the pitting on the shaft I think that’s caused by another issue (condensation/rust after flushing with fuel and it standing without oil).

I will check for wear on that on one but it doesn’t look worn on the teeth or uneven on the shaft.

Regarding the case it’s possible they are both distorted.
How would you check this?

[Designer]

I had the transfer and gearbox cases trued recently. Surprised how much they are out from factory

https://imgur.com/a/iv8pxBN

 

I had the transfer and gearbox cases trued recently. Surprised how much they are out from factory

https://imgur.com/a/iv8pxBN

Hi Steve220,

 

Looking at your pictures out of interest what are the bushes in your primary gear are they both original Deva material or is just the top hat one Deva. If they are both and you got them recently where may I ask did you get them from. I assume they are for a 998 A+ crank.

 

Regards Paddy

[Spider]

 

I had the transfer and gearbox cases trued recently. Surprised how much they are out from factory

https://imgur.com/a/iv8pxBN

 

I had the transfer and gearbox cases trued recently. Surprised how much they are out from factory

https://imgur.com/a/iv8pxBN

Hi Steve220,

 

Looking at your pictures out of interest what are the bushes in your primary gear are they both original Deva material or is just the top hat one Deva. If they are both and you got them recently where may I ask did you get them from. I assume they are for a 998 A+ crank.

 

Regards Paddy

 

 

It's only the 'top hat' bush that was made in Deva, but Steve's looked to me to be Silicon Bronze.

[lildeucecoop72]

Looks like the orig transfer case is bent or warped. If I put it on a dead flat surface it rocks ever so slightly, the other one doesn’t.

I did another test putting together that better transfer case with the box it came with, together with the original idler gear and thust washer. Torqued it up.

Difference between L-R is 0.0015” The bigger gap is is weirdly on the right side this time. I got this box untampered with. So I believe it came out of the factory this way. So I am quite frankly shocked at BL’s quality control… ;)

[Steve220]

I had the transfer and gearbox cases trued recently. Surprised how much they are out from factory

https://imgur.com/a/iv8pxBN

I had the transfer and gearbox cases trued recently. Surprised how much they are out from factory

https://imgur.com/a/iv8pxBN

Hi Steve220,

Looking at your pictures out of interest what are the bushes in your primary gear are they both original Deva material or is just the top hat one Deva. If they are both and you got them recently where may I ask did you get them from. I assume they are for a 998 A+ crank.

Regards Paddy

They're custom made silicone bronze. I have oil pressure fed thrusts as running high torque.

[Designer]

Hi Steve220 and Spider,

 

Thank you for your replies.

 

Regards Paddy

[lildeucecoop72]

OK I've managed to get the difference down to 0.001" either side with new thrust washers (0.005" Right and 0.004" on the left).

I will see if I can bring it down a notch further (0.005" and 0.004" or even 0.0045" and 0.0035") but the difference between remains the same, regardless of the changes in thrust washer thickness (0.001"difference).

 

Think that will have to do - I am not doing any more major work on this box - come what may (I drive for 4 months a year, and only on sunny-day jollies around the Oslo fjord).  

Edited by lildeucecoop72, 12 June 2023 - 11:09 PM.