[7dcrzr]

I have an SM420 transmission in my landcruiser, they are 4 spds with a 7:05.1 1st gear (great for rock crawling) and they are tough, heavy duty transmissions. Unfortunately, most of them are noisy and have a loud gear whine when running in 3rd/4th gear. I was told POWER PUNCH was a great additive for transfer cases and transmissions to quiet noisy gear whine down.

Has anyone used this product? any feedback would be great.... I am thinking about buying some to add to my tcase and transmission.

Thanks!

7D

[M&M CUSTOM]

Honestly, this thread is the first I've ever heard of it.

[7dcrzr]

Do you know of any other products designed to quiet down manual transmissions?

[M&M CUSTOM]

I've never had a loud transmission, or the vehicle was too loud in some other way that I never noticed, anyway.

[302 Z28]

Anything that is going to make the trans quieter is probably going to increase the viscosity of the lubricant, which can be undesirable. The cut on the gears are such that the noise is a byproduct. the more straight cut the gears are the noisier it is. That is why the M22 Rock Crusher is so noisy

Vince

[jim..]

I had a landcruiser,and they are very noisy,I thought it was just because the body had little if any noise supression and mine had no carpeting either.

What oil is in it now,if it has 80/90 gear lube like mine did,I doubt there is anything that will run much quieter than that.

[7dcrzr]

I am getting older, so the noise is definitely starting to be noticed more I am going to add some sound insulation on the floorboard, that will probably help a bit. These tranny's are notorius for being loud, the later SM465 is a bit quieter than the SM420, unfortunately 1st gear is not quite as low.

Thanks for the feedback.

[M&M CUSTOM]

[QUOTE=7dcrzr]unfortunately 1st gear is not quite as low.QUOTE]

6.55 first gear is not really all that much of a difference compared to the 420's first ratio.

I found that most of my noise from that area came up though the shifter handles of both the transmission AND transfer case, with the transfer case handle making most of it.