Iveco Transfer Case Explained

[goingbush]

Have my Transfer case out to fix some 'minor' Issues and found a solution to the catastrophic failure in the Low Range cluster. Iveco continue to throw $15,000 transfer cases at them under warranty.

Mine is out of warranty now , I made a simple alloy block to catch on the ends of the circlip & stop it moving about or coming adrift.

Its an interesting TC, worth a look

https://youtu.be/FN5hAZsQa7U

[Graeme]

The clip appears undersized, too light/flexible to stay fitted but perhaps would require a wider or deeper groove to take a heavier version.

[goingbush]

The clip appears undersized, too light/flexible to stay fitted but perhaps would require a wider or deeper groove to take a heavier version.

Correct, When I inspected mine , There was only 0.5mm of c-clip inside the groove one end was out of the groove, as in the very first image of the video, i could just pry it up with a screwdriver.

Iveco say they have revised the Transfer case by making the groove deeper, which if true, is a wasted effort as the new circlip is one and the same.

How can a company keep throwing $15,000 Transfer cases at these trucks when an engineering solution is so simple ??

[goingbush]

couple of photos showing the fix

Decking the "circlip lock" face,





Added inspection port for endoscope whilst i'm at it



My circlip lock has a tang that sits in the groove, ends of circlip sit against the lock so they can not float about and loosen. There is a small gap to allow for thermal expansion of the circlip.









showing clearance of high / low range selector fork .

[spudboy]

You're not afraid to take on major mods are you?! Good work.

[goingbush]

You're not afraid to take on major mods are you?! Good work.

what could possibly go wrong


Its out of warranty, Iveco can't fix them once they let go.
My plan was to install a divorced LT230 with Ashcrofts ATB and underdrive,
so I thought "what the hell, if I can't fix it I still have the LT230 option"

but this SCAM TC is pretty solid, its just got some pieces that are not thought out too well. Like the Oil seals , the Selector rods just have o-rings in the front housing , they are hardened , cracked and leaky , and TC needs full disassembly to replace a $1.00 o-ring !!! , so I'll put some proper seals on the front of the case, stupid little things like that .

plenty of meat on front of TC to put external oil wiper seals



And the input flange oil seal is on the inside of the input housing ???? Bizarre, I'll be making a new housing with the seal on the outside

- what were they thinking ??

[Graeme]

Is there enough material thickness on the original flange to enlarge the seal diameter leaving an internal lip? You could just remove the lip and fix the seal with appropriate seal retaining compound or possibly provide an external retaining plate fixed with 3 screws.

[goingbush]

Is there enough material thickness on the original flange to enlarge the seal diameter leaving an internal lip? You could just remove the lip and fix the seal with appropriate seal retaining compound or possibly provide an external retaining plate fixed with 3 screws.

yes, have removed lip , but having trouble seating seal flat , you just gave me an idea though, I'll remove some material and insert a sleeve with a collar for the seal to fit against. QED

[Hall]

Or you could put a circlip at the correct depth, thus making a square shoulder.
Cheers Hall

[Blknight.aus]

Nice work..

If the circlip originally fitted was the correct one but was put in an undersized grove it wouldnt sit in and be under too much pressure.

in theory (or more accurately as I prefer to see them) For an external gripping Circlip (like yours) the OD of the groove should be just a fraction larger than the OD of the circlip when fully released and the shoulder of the groove should be in the 1/2-2/3 of the clips width. and for an internal gripping one a firmish fit in the range of the clips relaxed ID+ 1/4-1/3 the clips material thickness. and the same groove depth.

I wonder if the Tcases are suffering because some engineer had a numpty day and specced up the dimensions of the groove on the wrong set of tolerances?