Any advice on M5 transmission rebuild?

[cbose]

I've got the usual syncro problems in a 5MT with 200,000 km on the clock.
The worst is the 4-->3 downshift which is at the point to need a double
clutch to avoid chewing up the gear. We have a good independent subaru
mechanic here who says the following: trans fluid change MAY help a bit, for a while, but
the only long term solution is to replace the syncros. (BTW he runs only ELF synthetic
in all his customer's cars) His quotes: full R+R plus a new clutch $1500 - 1750NZ.
My clutch is ok and I can remove my own trans. If I bring it in he will charge me about
$200NZ for parts (syncros and 2 main bearings -- remarkably cheap!) PLUS
approx 8 hours of bench labour which he says is 'mostly cleaning' since the case
uses no gaskets and needs to be spotless to get a good seal. We're talking here
about a stock rebuild, by the way -- this is a grocery getter, not a racer!

Ok, so why can't I do this myself? I'm pretty good at cleaning

Assuming that I get a shop to press on the new bearings, are there any
other special tools requried. Are there delicate shims to set up or something
that it would be best to have an experienced person do?
In other words, has anybody rebuilt their own trans. and if so, did it work
out and how tricky a job was it?

thanks, Chris

[entirelyturbo]

(BTW he runs only ELF synthetic
in all his customer's cars)

There's your problem right there. This guy doesn't know that you should NOT run synthetic gear oil in Subaru manual trannies...

You REALLY need to skim through my stickied thread at the top of this forum, and try the remedy that fixed it for me. Your tranny might still be A-okay, but grinding gears because this fool put synth in it...

[cbose]

Subyluvr2212

You REALLY need to skim through my stickied thread at the top of this forum, and try the remedy that fixed it for me. Your tranny might still be A-okay, but grinding gears because this fool put synth in it...

Yes, I've already seen these threads. You've tried harder than most to sort it out and you are
probably right. Local subaru dealership uses Castrol dino. But you have to admit there
are lots of different views on this expressed in the thread. Certainly, I'll try a fluid change
before taking any action to pull the gearbox.

The mechanic should know what he's doing. He was the head mechanic at the
local subaru dealership before he left to start his own (very busy) shop. When
he said 'synthetic' I tried to look surprised, and said I had heard (through reliable
sources, of course!) that synthetics don't work too well, but there seem to
be lots of different opinions on the matter -- he smiled and said something
to the effect that here is always no shortage of opinions about oil. Maybe
he left the dealership over argument about tranny fluid

I wanted him to say dino; I really did. Here in NZ 4 litres of Castrol synthetic will set you back
about $90 (or $50US) I picked up 4 litres of Castrol Multisync(?) dino for $50
but haven't put it in yet. Strange thing though: the same amount of elf synthetic
is only $22 . . . go figure.

Chris

[entirelyturbo]

The only good thing about this is: if the dino oil doesn't do it for ya, then yeah your tranny probably could use a refreshing internally. There's not much else to fix it. You do have ~160,000 miles...

However, I keep reading thread after thread on the USMB of people having terrible grinding with dino and synth fully fixes the problem. The other thing I noticed is that all the people that say this, mostly live in cold climates. I wonder if the properties of synth when it's cold are more suited for Subaru transmissions. My theory is that when the oil is cold, it's thick enough to make up for the fact that it's otherwise too slick. I know that down here in FL, it's quite hot, and I'll bet that when the synth gets thin, it offers no guard against grinding.

But yet again, it seems that my gears are engaging more positively now that it's in the 40's and 50's F here in FL, with the dino oil...

But nevertheless, if and when you decide to get the tranny rebuilt, ask them to be double-sure they put the newest "updated" synchronizer cones in it. I remember reading somewhere that the newer synchros have little holes in them to allow the oil to escape more quickly, helping the gears engage more smoothly and quickly...

[cbose]

Got the elf 'synthetic' into the transmission. The $22 stuff. Turns out it is
in fact a GL-5 dino oil, so now everyone is happy. Except my transmission.
The 4-->3 syncro is definitely worse now with the fresh lube. The oil
that came out was very dirty, and the mag drain plug was covered with
black metal oxides and some fine shavings, so I guess the syncro's are
really gone. Now I just need to decide between the $500 rebuild by the
subaru expert, or the $500 wrecker transmission with the 30 day warrantee

Neither very attractive options on a car I will be selling in 6 months!

chris

[cruznz]

maybe you could add some sort of additive to it to help it last the 6mths until you sell it.
I'm sure some sub enthusiaist would by it at a reduced price once informed of tranny condition..........just a thought