80 series unknown drive line issue

Submitted: Friday, Jul 31, 2020 at 10:16

ThreadID: 140304 Views:9560 Replies:6 FollowUps:8

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Mark 80

Hi Guys,

I'm looking for some help to see if anyone has run into the problem I'm currently having with my manual 96 DX 80 series.

So what kicked it off was trying to take off at a set of lights on a hill,

As I released the clutch I started moving but then once I started to accelerate more a loud clunk and shudder went through the vehicle and lost drive forward. I tried again, the same thing but managed to feather the clutch to get enough drive to get around the corner.

Now on the flat, I tried to get going again and this is what I think I have found.

I can get take off, get up to speed and change gears ok (all the way up to 4th), the problem starts when I accelerate and put too much torque through the car. this is when the massive clunk sound happens and I lose power (power moving forward the engine is fine).

This also happens in reverse.

So my question is what is it that could be causing the problem? gearbox, transfer case, rear dif?

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Reply By: RMD - Friday, Jul 31, 2020 at 11:32

Reply By: Nomadic Navara - Friday, Jul 31, 2020 at 12:57

Reply By: Member - McLaren3030 - Friday, Jul 31, 2020 at 13:05

Reply By: axle - Friday, Jul 31, 2020 at 15:03

Friday, Jul 31, 2020 at 15:03

If not whats mentioned

Transfer case input gear/shaft wear.

Good luck

Cheers.

AnswerID: 632776

Follow Up By: RMD - Friday, Jul 31, 2020 at 16:05

Friday, Jul 31, 2020 at 16:05

Axle
Does that mean the shaft has worn/moved to allow the gear teeth to jump? If shaft worn to that extent it would have been making a fair amount of noise which would have been evident when driven. Just bearings not so good causes a loud noise while driven. Maybe the change ring and associated selector moving away from High position, a bit like the lever being moved causing the same symptoms.

FollowupID: 909653

Follow Up By: axle - Friday, Jul 31, 2020 at 18:01

Friday, Jul 31, 2020 at 18:01

RMD,

I'm thinking internal wear in the gear making it jump on the shaft splines under load if the lot is worn But it would have to have done a lot of work. Who knows , hope it the simpler things for his sake ... lol

Cheers.

FollowupID: 909657

Follow Up By: RMD - Friday, Jul 31, 2020 at 19:08

Friday, Jul 31, 2020 at 19:08

Axle.
I see what you mean. From what I can see in my very similar 60 series diagrams the dogs on the dog clutch/ring may be worn. That would be felt in the transfer lever when it happens.

FollowupID: 909661

Follow Up By: Bob Y. - Qld - Friday, Jul 31, 2020 at 19:46

Friday, Jul 31, 2020 at 19:46

Tha DX models, from what I recall, had the standard transfer case, as fitted to the 79 series utes & 78 series troopies. The large nut on the t/c input shaft, that holds the dual gear sets tight, would rarely be retightened, so the gear sets move about on the splines, promoting wear. All as Axle suggested!

From the few examples I’ve seen, it’s either go or not. Haven’t heard of spasmodic movement with this fault. Maybe the gear set is moving enough to gain some momentum?

Bob