Manual Transmission -- Internal gears failing?

You guys are great… I listen most weeks.

I’ve got a 96 Honda del Sol with 135,000 miles on it… and want to keep the car indefinitely. I’ve always had all maintenance done as needed.

For about the last 6 months, as I’m going up in RPMs in 1st gear, the sound of the transmission will all of a sudden get noticeably louder. Not an odd sound, just louder. This may be happening in 2nd gear too… but not as noticeably. Nothing sounds different in 3rd, 4th, or 5th… and it functions just great.

I’ve got the original clutch… and a service shop I used to go to said they thought I had plenty of life on the clutch. The service shop I now go to said that this sound was indication of internal transmission bearings going out… and that… at some point, I’d need a new transmission… and the bonus is I’d get a new clutch in the deal. They suggested a refurbished, used transmission… that they could get… and that the whole replacement should be ~ $1800.

Does this sound right to you? Are these bearings that are an integral part of the transmission and can’t be replaced ? How soon would you think it would fail… and will failure mean the transmission just locks up?? Does their price sound right? … so many questions.

Any help would be appreciated … I know you guys know your stuff.

Thanks!
… Rick

Is the sound affected by how quickly you are accelerating? Is the noise present if you release the throttle and decelerate?

The bearings can be replaced, but that is not the end of it. The bearings are pressed onto the shafts inside the transmission, some inbetween gears. Once you decide to replace them all, then you should replace synchro rings and any damaged parts, like questionable gears and shift dogs. A total tear down and rebuild can cost around $3-4, 000. A good used unit is less than half, as you were quoted.

I own and drive an '88 Toyota. It has 286, 790 miles on it, but I love it. But, at this age, you will begin to see things fail at a regular pace. The worst will be electronic modules and expensive to reach gaskets, like the rear main seal. The gaskets age with time, so there’s not much you can do about that. the mofules just flat stop working. And both can let go at any time.

Good comments above. Some transmission noise in first gear is normal, and the faster you go in first gear, and the more load – like going uphill – the more noise. But I’m assuming the OP has noticed the transmission noise level now is worse than earlier. And it isn’t normal for the noise level to increase dramatically at a certain rpm. So there may indeed be something amiss. Still it might not be a transmission bearing problem. Not yet anyway. OP should have the transmission oil level inspected, as it might be low. And if the transmission oil has never been changed, now would be a good time for and drain and refill with a fresh batch.

Rod Knox – Nope, slow or fast acceleration, same noise kicks in a certain RPM. Decelerating causes the noise to instantly stop.

BustedKnuckles – That seems reasonable… thanks.

GeorgeSanJose – Transmission oil’s been changed on schedule… and they said it looked clean at that time, but that was before the noise started.

Thanks to all for your help !

Check the motor mounts and the heat shields on the exhaust system…This may not be your transmission at all…Try this. With car warmed up and in a quiet area, engine running, transmission in neutral, depress the clutch to the floor and wait a few seconds. Then SLOWLY release the clutch pedal. Can you hear the sound of the transmission bearings starting to spin as you release the clutch? If not, if you hear nothing, then the transmission is probably okay. If the point of engagement is quite evident, you hear the transmission main-shaft and counter-shaft spinning, the tranny has some wear but it STILL may be serviceable…

Also, your transmission drain plug may have a magnet built into it to collect and hold wear particles. You might take a look at that…If it’s covered with shiny metal particles then you have a transmission problem. A small amount of black goo is normal…

1st and 2d gear are the rearmost ranges on the transmission and engine torque increases as rpms increase under acceleration so the condition might indicate a worn output bearing or a failing mesh at the final drive. Either way, the mechanic’s diagnosis and estimate sounds quite reasonable.

And FWIW, my questions were to determine if a mount might be failing, @Caddyman. Great minds…