I have a 95 Tacoma, 4wd manual transmission that rumbles - I think up front - when I accelerate at around 40 mph and above. It gets quieter where I coast, or press in the clutch. Anybody have any ideas what it could be?
Misfiring spark plugs is a pretty good reason.
Hmmm… might be; I recently replaced my spark plugs and wires - about a month ago.
I’ve also replaced my front springs and struts, rear shocks and leaf springs at that time. I greased my driveshaft a couple of weeks ago too. (I must love being under my truck)
Could it also be an alignment or wheel balance issue?
Yes, try rotating tires front to back. If no change, problem with the front end.
I’ll try that.
I also changed the front and rear differential fluid as well as the transmission fluid and transfer case fluid.
It’s got about 350k miles, and probably about that much more left in her …
You said you greased the driveshafts. Did you notice any play in the rear u-joints? I’ve had failing rear u-joints show up as a vibration at speed. Check front CV joints also. Couldn’t be too mad at Toyota if any of those failed at 350k.
Read your post again. Is the rumble just a noise, or have any vibration to go along with it?
I didn’t notice play in the rear u-joint when I greased them, but good idea! I’ll check it out.
Don’t forget the cv joints in the front. They’re still turning in 2wd, although they’re not pulling. If they’ve got a lot of play, they could vibrate. If they are worn enough to vibrate, I think they’d probably click and pop when turning in 4wd.
If this is happening in 2wd mode everything from the transfer case output to the front wheels seems unlikely given the clutch/coasting relationship. My guess is either problematic manual transmission bearings or rear differential problem. Check the fluids. The other thing that came to my mind is the crankshaft thrust bearing.
Thanks, I will.
Road to 700k miles x)