I had a friend who owned a tranny shop made the recommendation to me that I should add an LSD additive (for posi-track & similar ones) to my transaxle to improve shifting.

 

Changing oil and using Mobil 1 75w-90 helped upshift from 1-2 and 2-3 but downshifts for those gears is still very difficult - I don't care about 2-1, but I need to downshift from 3-2.

 

Any thoughts on this notion of LSD additive? I kinda tried it before I changed my gear oil and noticed a very slight improvement, but any other thoughts would be good too. My friend with the tranny shop mainly did automatics, so I don't know how good he is with manuals.

 

I am a little worried about it eating my synchros, as I have no idea as to how it is supposed to work, chemically speaking

 

My car is a 1985 Subaru GL Wagon 4WD 5 speed D/R, originally carbed (now spfi).

 

yes a tranny rebuild is the surest way to solve the prob, but I don't have time or $ to do it

I run 75W-90 royal purple gear oil and it works great!

btw, you'll only need 1 bottle for a subaru

nsane']btw' date=' you'll only need 1 bottle for a subaru[/quote']

not if you have a MT 5-speed 4WD dual range transaxle - that is the front gearbox, transfer case, and front diff - they're all in one unit & share same lubricant - 3.5 quarts if you empty it properly (it takes time for everything to drip out) - I checked the dipstick as I was adding to make sure I did not overfill, and I was on a very level surface

 

you only need only about 3/4 quart for rear diff

I use redline 75W-90NS for the older tranny in my '91 Legacy. Either it's working or I've changed my shifting habits to compensate for it. Another thing to consider, is your clutch cable properly adjusted? Too much pedal play means your clutch will not disengage properly and cause difficult shifting.

I'll consiter that - It is actually getting better with use - I think there was just that much gunk in it, and it is taking time to free up - or I am also shifting differently and don't know it

 

I have no peddle play in my clutch - in fact my friction point is very high because my clutch is about due for replacement (no adjustment left - argh) - I will wait until the summer for that though!

 

Thanks for the advice.

oops, 1 bottle i meant for the rear diff..

 

its about 3.5 bottles of 75w-80 in the manual transaxle..

nsane']oops' date=' 1 bottle i meant for the rear diff..

 

its about 3.5 bottles of 75w-80 in the manual transaxle..[/quote']

 

So where is the best place to buy it, since I'm going to need 4.5 bottles of it?

just buy the regular gear oil for the tranny.

i might be exposing my ignorance, but my xt6 has no lsd in the tranny. my dual range has no lsd in the tranny. so which subarus have a lsd in the front?

 

probably legacies.

you only put the lsd addative to the rear lsd diffs afaik.

no subaru I know of has an LSD in the front (at least from the factory)

 

my friend suggested the additive (a small bottle you add to the oil) to help with the shifting because it is not synchronizing well - supposedly the difference in the nature of the viscosity would help? - I don't know for sure though - I know about all "regular" oils - but I have never messed with an LSD diff, so I don't know about LSD diff oils

 

yes, it would be a band-aid cure - but I don't have time/$ to rebuild a tranny