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Recently a grinding noise starting coming from under my jtruck, it seems like when I get up to 80km it starts making the noise. I’m questioning weather its something to do with third gear because it shifts twice then once I speed up and it’s about to shift to third starts making the noise but idk if that’s a coincidence or has something to do with speed but I’ve attached a video bellow of the noise.

Let me know if the link works because I’m not sure how to post a video here.

Does the truck still accelerate when the sound happens?

How does the transmission fluid look?

Its certainly a sound I have never personally heard.

Stuka wrote: ↑Sun Apr 07, 2024 9:56 pm Does the truck still accelerate when the sound happens?

How does the transmission fluid look?

Its certainly a sound I have never personally heard.

I do need to get new lines for it because it does leak transmission fluid out them, I’ve been topping the fluid up until I can get the lines but I am also thinking that might have something to do it with. It starting making that noise then I tighten the lines and topped it up on fluid and it stopped making it, I was able to get up to 120km without it making a noise but it started it again so I thought I’d get some other opinions on it.

yep, check your oil level.

Also the J truck has the TH400, the transmission modulator can leak after a while, it is on the right side or passenger side of the transmission, the modulator is connected to the intake manifold vacuum... when the modulator start to leak, upon warm restart a lot of trans fluid can be suck by the engine and a large cloud of smoke will exhaust from the tail pipe.

letank wrote: ↑Tue Apr 09, 2024 10:35 am yep, check your oil level.

Also the J truck has the TH400, the transmission modulator can leak after a while, it is on the right side or passenger side of the transmission, the modulator is connected to the intake manifold vacuum... when the modulator start to leak, upon warm restart a lot of trans fluid can be suck by the engine and a large cloud of smoke will exhaust from the tail pipe.

So before I went for a drive yesterday I check the transmission oil level and it’s full. Took it out and still making the noise so I’m kinda of thinking something might have broke off and is now rattling in the transmission. When I get up to 80km you can hear a rattle before it starts grinding but I don’t know why it would happen only when getting speed if that is the case it should be happening all the time. So idk if I should start looking for new transmission.

I wonder if the vacuum modulator is unable to fully move and its getting stuck between gears or something?

nylajean44 wrote: ↑Wed Apr 10, 2024 2:43 pm
So before I went for a drive yesterday I check the transmission oil level and it’s full.

Sorry to be finicky here, to check the transmission oil level: the engine is running and you have the transmission in neutral after having switch to all the gears... but the oil should also be at operating temperature.

thinking about weird noises... check the front disk brake shields, they are welded in 2 spots and the 3rd spot is bolted... after a while the welds break... You can remove them...I have been shieldless for a long time...