Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

SeaFoam in a Manual Trans?

Featured Replies

'96 OBW 200k, 5MT

 

I recently replaced a bearing in my trans. It was the big tandem roller bearing on the rear of main shaft that I replaced because the cages had grenaded. I picked all the pieces of cage I could find, but much of it was reduced to a shavings that were coating much of the case surface.

 

I cleaned off everything I could reach, but I didn't disassemble the pinion shaft (the shifting on this car is flawless, before and after this hiccup) so I'm wondering if seafoam might help clean things out a bit.

 

I was planning on running some cheap oil, changing in about a week, then again with the next couple of oil changes depending on what kind of "shaving content" I had on the drain plug (magnetic) but I saw a bottle of seafoam on my shelf and started thinking that it might help out.

 

Basically seafoam is like kerosene (right?) so it would thin the gear oil out and maybe "scrub" the surfaces of the trans of metal shavings.

 

I have a fifty mile commute to work, so I was thinking of dumping in half a bottle at work then driving it home and doing a fluid change then, so that would be fifty miles of mixing.

 

What think you oh great holder of subaru knowledge?

 

Thanks!

 

Will-

Edited by lostinthe202

I like and use Seafoam, and as you say, it is more of a solvent. It has merit when added to the oil or the gas. However, I don't think using as you have suggested in your AT is a good idea. Your AT is designed to work with ATF, and I don't think Seafoam is promoted as a product to add to your AT, let alone have the property to "scrub" fine metal particles from your trany's internals.

 

If I had your situation, I would be inclined to add, then drive a little, and drain ATF to your trany three or four times to get the trany fluid as clean as possible. Then leave well enough alone. You have already said that your trany works great, so if it ain't broke don't fix it.

 

There is a fine mesh screen that you can change upon dropping the pan on the AT, but I would not recommend doing that. I have never seen a screen block any metal grit, let alone the fine particles that you have described. Also, resealing the pan is very difficult, and still presents potential for fluid leaks.

  • Author

Oops! My mistake, I should have mentioned in my post that I've got a manual trans.

 

I've edited my post to that effect!

I would go for it. Drive it around for a day or two under normal load and then drain it and fill it up with some fresh gear oil. I think it would only do good stuff for your trans.

  • 3 weeks later...

don't use anything to thin your fluid!!! it is designed to run a certin weight. when you drive the fluid gets "thinner". drain the fluid clean the magnet and refill. you don't want to try to harm your trans.

  • Author

Too late.

 

I know it thins the oil, but I wasn't planning on having it in there for very long. I added it at the gas station (15 miles from my house) then drove it home and did and oil change.

you poor guy, a 50 mile commute is just terrible.

anyway once you get it cleaned out id use

31K8EH83WEL._SL500_AA280_.jpg

id use it in any manual tranny

Basically seafoam is like kerosene (right?)

Seafoam is pale oil, naptha, isopropyl alcohol, and water.

you poor guy, a 50 mile commute is just terrible.

anyway once you get it cleaned out id use

http://ecx.images-amazon.com/images/I/31K8EH83WEL._SL500_AA280_.jpg/IMG]

id use it in any manual tranny

 

Hm synchromesh manual transmission fluid? I don't think that stuff is GL-5 rated so it would not be for use in a Subaru manual trans, not enough protection for the front differential hypoid gears.

  • Author

Thanks for the input fellas. My trans shifts beautifully, always has, which is why I went through the trouble of replacing the bad bearings in it. The rear double roller bearing on the main shaft had lost both cages. Parts of them were ground into powder and parts were in the process but still kicking around the case.

 

I used the seafoam to help facilitate the removal of the metal paste that was left behind from the eaten cages.

 

Will-

Hm synchromesh manual transmission fluid? I don't think that stuff is GL-5 rated so it would not be for use in a Subaru manual trans, not enough protection for the front differential hypoid gears.

 

does it really call for gl5? GL4 or GL5 attack the yellow metal synchros

IIRC, redline and synchromesh are gl-4s but with additives for use with yellow metals, could be wrong though

Yes soob manual trans do call for GL-5, it needs the extreme pressure additives. Synchromesh is more for Honda's and stuff that are transverse mount and don't have hypoid gears in the diff.

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.