Forum:
Ive got a 1985 F75 Rocky which is working perfectly fine except that i can't shift from third gear down to second. I can shift up gears fine but the third to second dosent want to go in. Can anyone tell me what the problem could be and how i can fix it. cheers
its a 2.8 turbo diesel if
its a 2.8 turbo diesel if that helps.
Nuts
Usually the mainshaft nut loose on the transfer case, this causes the shaft to float about and difficulty in engaging gears.
On the rear of the transfer case is an aluminium cover shaped like a bra, inclined at 45 degrees, remove this and locate the upper shaft on the left hand side. Using a 6 point socket, tighten this as tight as you can, 12 point sockets will slip, or damage the nut; peen the nut flange tightly into the keyway to stop it from coming loose.
This cures the problem in most cases, if not it will be a worn gear, worn synchro, or play in the bearings.
ok thanks alot for that.
ok thanks alot for that. I'll give that a go and see if that fixes the problem. Ive just got another quick question, im pretty much a complete novice, could you explain how exactly the transfer case affects the gears changing in the gear box? cheers
Nutty
The mainshaft is in two halves with a centre bearing, if one of the halves floats about it causes the syncromesh, and detent assenblies to becone misaligned. This misalignment means the assemblies are too far apart, or vertically and horizontally misaligned to allow the synchromesh and selector mechanisms to work correctly. As a result of this, the gear selectors run out of travel to allow the gears to engage correctly. Usually, the first signs are difficulty selecting second gear, then first gear, then all gears.
The nut pulls the shaft tight to the rear bearing which locates the shaft in its correct position. and aligns everything again, in its correct position.
Leaving the nut loose causes the edges of the gears to wear prematurely, and compounds the problem.
If you can find a free knackered box, have it and strip it down, it will become self evident how well made the gearboxes are, and just how tight the tolerances are for what is essentially, an agricultural gearbox.
Nutty
Sorry, forgot to mention, the mainshaft runs through the transfer case, it provides the drive for the four wheel drive, and also the low range gearing. It is the rear transfer case bearing which gives it its alignment, all other bearings in the gearbox float.