Bugger- Put some Silkolene Syntran 5 in the box and now its crunching going into gear
#1
Bugger- Put some Silkolene Syntran 5 in the box and now its crunching going into gear
Box is an 80k miler on an old 93 WRX and being as I'd had her 30k miles I thought I'd treat it to fresh trans and diff oil from the helpful chaps at Opie.
On the old oil I used to beat the synchros into 2nd very occasionally with a real tug on the lever, after the change it now crunches into every gear except 4th unless I take an age when changing.
Why have the synchros stopped working with the new oil? The specs seem ok, fully synth 75W/90? Theres 4 litres in the box, just under a litre in the diff, no leaks, 2000 miles on the new stuff and the levels are all good.
I've got no idea what the old stuff that worked better in the box was, anyone else had this/got any ideas?
Many thanks
Andy
On the old oil I used to beat the synchros into 2nd very occasionally with a real tug on the lever, after the change it now crunches into every gear except 4th unless I take an age when changing.
Why have the synchros stopped working with the new oil? The specs seem ok, fully synth 75W/90? Theres 4 litres in the box, just under a litre in the diff, no leaks, 2000 miles on the new stuff and the levels are all good.
I've got no idea what the old stuff that worked better in the box was, anyone else had this/got any ideas?
Many thanks
Andy
#3
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I tried Syn-5 in the box of my 99my when I had it and got crunching from 4th to 5th above 4k Drained it and replaced it with Castrol Syntrax (Now called Driveline) and this cured the problem. It's not that Syn 5 is dodgy, it's just that it's too slippy for the synchro! Some people have the problem and some don't. I put the Syn5 into the box in the wifes Primera where it works fine!
JohnD
JohnD
#4
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i have to say i thought that the redline Lightweight shockproof i had before was better than the silkoline i have in there now.....the box feels much looser..
#5
Nuts. I was gonna buy Syntrax originally but got advised to buy the dearer stuff by the guy at Opie. Thats cost me. Cheers guys, guess I'll be ordering some Syntrax ASAP then. I'm still cringing at the noises from the video going round the ring. Hope it hasn't damaged the box, I'll see if any new metal is clinging to the magnetic plug.
#6
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Originally Posted by kwakman
Nuts. I was gonna buy Syntrax originally but got advised to buy the dearer stuff by the guy at Opie. Thats cost me. Cheers guys, guess I'll be ordering some Syntrax ASAP then. I'm still cringing at the noises from the video going round the ring. Hope it hasn't damaged the box, I'll see if any new metal is clinging to the magnetic plug.
If you get Driveline (Syntrax) get it straight from Castrol www.castrolclassicoils.co.uk
JohnD
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#8
Former Sponsor
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There are many people on here using Silktran Syn 5 75w-90 with no problems at all.
Spec wise it's a 75w-90 gear and diff oil which meets GL4/GL5 specs. The Castrol Syntrax is also a 75w-90 gear oil meeting GL3/GL4/GL5.
The only difference is that the Silkolene is a fully synthetic and the Castrol a "part-synthetic" as they term it.
I can only assume that the "older" boxes don't like it due to the fact that it uses no petroleum basestocks.
Semi-synthetic or part-synthetic is fine but if there is more power through the box than stock or you are doing trackdays then semi or part will lose viscosity too quickly and will not necessarily be up to the job.
There is nothing wrong with the quality of the oil, we use it in 1000bhp cars however there does seem to be some quirky element with the synchros here that doesn't like very high quality oils.
Has anyone here experienced this with Motul Gear 300 75w-90?
Cheers
Simon
Spec wise it's a 75w-90 gear and diff oil which meets GL4/GL5 specs. The Castrol Syntrax is also a 75w-90 gear oil meeting GL3/GL4/GL5.
The only difference is that the Silkolene is a fully synthetic and the Castrol a "part-synthetic" as they term it.
I can only assume that the "older" boxes don't like it due to the fact that it uses no petroleum basestocks.
Semi-synthetic or part-synthetic is fine but if there is more power through the box than stock or you are doing trackdays then semi or part will lose viscosity too quickly and will not necessarily be up to the job.
There is nothing wrong with the quality of the oil, we use it in 1000bhp cars however there does seem to be some quirky element with the synchros here that doesn't like very high quality oils.
Has anyone here experienced this with Motul Gear 300 75w-90?
Cheers
Simon
#9
I guess its an older box issue then, although JohnD had it on an MY99?
Fair play to Simon, hes offered to refund me for the oil, I'll report back what happens when I put semi-synth in.
Im running stock power, well less than 300 bhp anyways, and avoid clutch dropping starts etc.
Fair play to Simon, hes offered to refund me for the oil, I'll report back what happens when I put semi-synth in.
Im running stock power, well less than 300 bhp anyways, and avoid clutch dropping starts etc.
#10
Former Sponsor
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I've asked Silkolene to comment on whether there is a logical explanation and will post the reply here but this is the first time that we have experienced this on an Impreza and I'd like to get to the bottom of the problem from an oil perspective.
If it turns out that synthetics are better for synchros then it must be an addative issue, we'll see.
Cheers
Simon
If it turns out that synthetics are better for synchros then it must be an addative issue, we'll see.
Cheers
Simon
#11
Top Marks for Opie. Simon has not only refunded me but is sending me the semi synth to try FoC. Dont think I've ever had customer service like that. Will report back on the oil change when its done.
#12
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Silkolene silktran syn5 worked wonders for my MY95 box, Almost totally elliminated the crunching. Some strange quirks, have these Subarus !
#13
Ecu Specialist
It is a known thing with this and many other fully synthetic gearbox oils, I first experienced the effects (using the Sylkolene although as mentioned others are the same) back in 1999, quickly reverted to Shell semisynth and all was fine. The Subaru syncros don't always seem to bite properly when a fully synth is used.
Definately a gearbox design issue but, as mentioned, not something new and not consistent.
bob
Definately a gearbox design issue but, as mentioned, not something new and not consistent.
bob
#16
Ecu Specialist
Yes I have John, it was "not bad" but the Castrol was better, in between I made a big mistake and put in some Redline Heavyweight shockproof, box nearly seized when cold, could hardly move the gear shift. Took three changes to finally get rid of the Redline.
bob
bob
#17
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An oddity indeed and seems inconsistant. I wonder if the condition of the synchros play a part in the results.
Anyway, here is Silkolene's answer.
Quote:
Yes, it could be ‘more slippery’; a more ‘commodity’ grade 75W/90 may be better. Even more likely is that the Syn 5 is higher viscosity. The trouble with SAE ratings is that they’re a mile wide! If the transmission runs fairly cool, the higher viscosity could be reducing synchro cone friction.
Unquote:
Cheers
Simon
Anyway, here is Silkolene's answer.
Quote:
Yes, it could be ‘more slippery’; a more ‘commodity’ grade 75W/90 may be better. Even more likely is that the Syn 5 is higher viscosity. The trouble with SAE ratings is that they’re a mile wide! If the transmission runs fairly cool, the higher viscosity could be reducing synchro cone friction.
Unquote:
Cheers
Simon
#19
Former Sponsor
iTrader: (9)
Originally Posted by kwakman
Oil Change done; crunching has gone; synchros seemed to be operating normally again. Thanks again to Opie for sorting the problem out.
Andy
Andy
I suppose the next question here will be what did you use?
For those that are interested, this:
http://www.opieoils.co.uk/TechSpecs/...5W-90_3170.pdf
Thanks again for the feedback, much appreciated
Cheers
Simon
#20
Oh dear. Here I go again.
I've got a transmission oil change coming up.
99 UK Turbowagon. Only 34K miles.
Last two changes I've used Amsoil Series 2000 75/90. Very expensive and called fully synthetic but as oilman has said before Amsoil don't release details.
Now I've had no problems with this oil but was thinking of changing to Silkolene as I use that in engine.
Now I'm not sure what to do.
I must suffer from SPS.
Scooby Paranoia Syndrome.
I've got a transmission oil change coming up.
99 UK Turbowagon. Only 34K miles.
Last two changes I've used Amsoil Series 2000 75/90. Very expensive and called fully synthetic but as oilman has said before Amsoil don't release details.
Now I've had no problems with this oil but was thinking of changing to Silkolene as I use that in engine.
Now I'm not sure what to do.
I must suffer from SPS.
Scooby Paranoia Syndrome.
#22
Scooby Regular
iTrader: (5)
Originally Posted by JohnD
I tried Syn-5 in the box of my 99my when I had it and got crunching from 4th to 5th above 4k Drained it and replaced it with Castrol Syntrax (Now called Driveline) and this cured the problem. It's not that Syn 5 is dodgy, it's just that it's too slippy for the synchro! Some people have the problem and some don't. I put the Syn5 into the box in the wifes Primera where it works fine!
JohnD
JohnD
JohnD
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