Hi all -

1994 D1 with R380 manual trans. I've got a worsening problem that started ~3months ago and is now more prevalent. Basically when slowing down (15mph to 0), as soon as I push the clutch in and/or put neutral I get a banging / clunking / tapping clunking sound from the trans tunnel area. Happens in 4Hi, 4lo, and neutral on LT230 transfer box. Doesn't seem to happen (or at least I can't hear it) at higher speeds/revs. Checked all of my wheel bearings and splines. Differentials sound fine when spinning manually off the ground. Replaced rear prop shaft with no change. Removed from prop shaft with no change.

Been considering an Ashcroft replacement for both the r380 and transfer case. Maybe time to pull the trigger but before I do want to make sure I'm not missing something obvious or easily repairable...

Any help would be appreciated!

 

What color was the transmission fluid?
When was the last time you changed it?

 

Hey thanks for the reply. Changed the fluid when I first got it last year. Looked a little dirty but not too bad and no large chunks. Also changed it when these symptoms started so got some fresh redline MT in there.

 

So that it's clear to me, you are getting this clunk when parked, transfer case in neutral, and you engage then disengage the clutch?

My first inclination would be to look for something physically hitting the tunnel, and to check the condition of all the mounts (engine and transfer case).

 

No sounds when vehicle is stopped or when traveling at speed. Sound only heard when slowing down from 15mph to 0mph and depress the clutch. Almost feels like this then causes something in the transmission or gear to spin and make this clacking/tapping sound.

Makes no difference in 4Hi, 4Lo, locked transfer box or not.

 

Ah, ok. You mentioned having the transfer case in neutral in the first post, and I wasn't sure if you were shifting into neutral while moving or sitting still.

So you're off the gas (compression braking) decelerating from 15 to 0 and pushing in the clutch at some point before coming to a stop... and that's when you hear it. Is it a single sound, or does it repeat?

Interesting situation. If it were me, I'd be exploring everything before dropping the dollars for another transmission and transfer case. They aren't cheap, and I'm not rich.

 

Thanks Banzi Jimmy - sometimes I think you're the only one who reads these posts lol.

The sound is continuous (maybe a few claps a second) and doesn't change in speed with the car speed. It does wind down and cut out as the car stops but it doesn't seem linked to the wheels/prop shafts. Almost feels like something gets spun up or freed up in the trans when the clutch pressure comes off and is free to shake/rattle/spin.

Good advice on looking for other causes before pulling everything out. So far checked everything else that moves that I can think of on the drive-train. Next I guess I'll check things that aren't supposed to move as you suggest (mounts etc).

The rest of my transmission isn't really great either if I'm honest. Vague shifting, 1st and 2nd gear syncros went away over the last 10k. Might just be its falling apart in there lol. 145k on it as far as I know.

 

Well, I too have a '94 with a five speed so I can relate. And, I've had many manual trucks over the decades and done the clutches, etc. in them, so I have some working knowledge... but am no expert!

With the additional details on the sound, I doubt it's the mounts or broken mount-induced.

The only other thing I can think of outside of something internal to the transmission is the clutch... but the noise would be RPM linked. Since you're not getting the noise while sitting still, I think that rules the clutch out.

I think you've figured it out. About the only other "test" I could concoct is to see if the sound quits while still rolling. Flat lengthy road/parking lot, get up to a slow speed, push clutch in and hold, transmission into neutral and transfer case into neutral (if it'll shift easily; don't want to break anything in there), and listen. The internals of the transmission would gradually slow down to a, or almost a, stop with no input from either end... and it would confirm it's not vehicle movement related (something outside the transmission).

The only other question/thought I have is does the sound happen in any gear, or is it just one gear? Don't think this is anything that'll fix the problem, but more me being curious.

Have you called Ashcroft yet? Given their experience, bet they have seen this before.

Good luck! I think I'm tapped out on ideas.

 

I've got something like this too. Usually notice it at low speeds when coming to a stop and I press the clutch in. I have no idea what it is.
I'm probably not going to try to find out.. I'll either put in a good used Auto trans or buy a new R380 from Ashcroft.

 

Thanks FishEH I'll let you know if I figure it out. Got a tax return coming in hot and plenty of weekend time at the moment to try to get a new box in

The fact that it still does this while the LT230 is in neutral has me convinced it is the R380 but I will be pretty frustrated if it is the transfer case instead...