Is this noise my front differential?

[djdevon3]

1995 Mazda 626 2.0L Manual FWD (previously automatic).

I would like to preface this post by saying that my channel and this whole 2+ year journey of trying to fix my car is due to ETCG. He diagnosed a bad intake valve on cylinder 3 so I took off the head to have it fixed at a machine shop without any prior experience. Machine shop said sure enough that’s exactly what was wrong with the head. Great job ETCG. Reassembled and the engine ran great but the idle issue and vibration were still there. The more I learned about auto repair the more issues I found with the car. Ignorance is bliss sometimes. Dealership said the torque converter was causing the vibration so decided it was a good time to swap to manual. Got the torque converter out and sure enough it was all messed up. Only within the past couple of months did I finally figure out that low fuel pressure was playing havoc with my idle. My car had so many issues that went completely undiagnosed for about 8 years that knocking them out one by one the car was steadily improving.

Bought a $100 junkyard transmission. I did not have the money, space, or knowledge to pull it apart to inspect it. I slapped it in there. Took me 6 months to gather all of the parts for the swap by scavenging from junkyard cars. Got everything installed and it does run now however I’m getting a front end clunk which speeds up into a high frequency grinding or vibration. From doing research online right now my opinion is it’s the differential but I would like to run it by everyone here before seeking out a transmission specialist.

[video width=550 height=309 type=youtube]ZVKXdfSVQpo[/video]

Yes I make my own videos but I’m a DIY’er with no experience. My videos and perspectives hopefully reflect that. This is my friend test driving the vehicle for his perspective. He’s also a DIY’er.

[video width=550 height=309 type=youtube]tOzBGbi5MoM[/video]

The car will slightly jerk forward and backward as if it’s switching between coasting mode and engine braking effect. From what I’ve read online this is a symptom of a bad differential.

I’ve met a lot of great people on this forum that were extremely helpful when I started this endeavor including ECTG; the man himself. Yes it’s 3 years later and I’m still trying to fix this thing but now I’m dealing with an unknown manual trans instead of my automatic.

For those of you who might ask why I’m doing all of this. It’s my first and only car. I’ve owned my Mazda 626 for 19 years now. My 626 is me, I am my 626, we are one.

Topic

[Bill]

I can imagine what It’s like in the car as I had to turn the bass down on my computer speakers. The noise was driving me crazy….LoL

There has to be part of the engine, transmission or exhaust system touching the body or frame of the car. The mounts are rubber to stop the engine vibrations from transferring to the car. If one of them is not isolating the engine from the frame this noise will result.
Same deal with the exhaust system. If any part of the exhaust system is touching the body or frame or is not mounted in rubber where it hangs from the underside these noises will result.

Start by checking these areas and let us know what you find.

[djdevon3]

It’s definitely not the exhaust. I’ve checked over the engine bay after the swap and did find the axles making a little bit of noise. I have no idea if axles are supposed to have this much free play (lack of experience).

[video width=550 height=309 type=youtube]nM-ZwhwtIn8[/video]

That was the only thing I could find. Last week I jacked the front end up and used a crowbar on everything I could think of. Crossmember, ball joints, and engine mounts are good. I found a loose tierod and tightened it down then went for a test drive. Result: at least I don’t have a loose tierod anymore but the clunk and growl are still there.

This week I was going to swap out the battery terminals and found my external ignition coil bracket was very loose and knocking against the transmission. This is because the automatic bracket is much different from the way the manual transmission bracket is setup. I’m still using the automatic ignition system (car permanently in park via fooling the transaxle range switch). It does work but I don’t have the full manual wiring harness, distributor, or brackets that go along with that. I have yet to take it for a test drive after fixing the loose bracket because I don’t have the correct cable eyelets for the larger battery posts (different from my old terminals). Waiting to find some 4 AWG terminals to put on. Till then the car is sitting powerless in the garage.

[Author]

Replies