Gearbox oil supplier

OK my turn to ask for help :)

Renault megane, phase 1 gearbox oil. Haynes says Tranself TRX 75W/80W. Cant find it. Renault want 15 quid a litre and it needs 4 litres. I'm presuming its synthetic for that price. I know some gearboxes have copper(?) synchros instead of brass and non-synth will corrode them but im not sure if the megane fits that or not. Cant seem to find normal EP75/80. 80/90 would be too thick. Throw in EP80 dino oil or fork out

60 quid for 4 litres of the synth?

Anyone know of a decent box oil retailer? Halfrauds will charge a fortune for unbranded rubbish and my local motor factors said just to stick 80/90 in so im not inclined to go there. Any major retaillers i can get oil from on a sunday? :)

Ta!

Reply to
Coyoteboy
Loading thread data ...

I would think that mtx 75 as used in many ford boxes would be fine, any car shop should stock it

Reply to
mrcheerful

Hello, EP 75w80 is available from Partco. Surprisingly however, the cheapest place I could find it was at the local Rover dealers as they use it in the boxes coupled to the 1.8 Peugeot Turbo Diesel engine in the old 218 td. I wanted it for my 306 td.

If you need the part number for Rover, or the Unipart number for Partco, let me know and i'll see if I can find the bottle with it on.

Hope to help, Paul

Reply to
P A Latham

Well thanks all for your replies, i checked with various shops and they all had semi-synth 75-90 listed as the requirement but no-one had 75-80 in anything more than 1 litre tubs at =A310 a tub so we went with the suggested 75-90 semi-synth which we got 5 litres of for =A317. Box seems happier, nippier shifting and quieter - must have been well overdue, goes to show you cant trust full service histories - not worth the paper they are printed on. Found so many things on this car that the previous owner had entrusted to her garage but just werent done. Got reams of receipts including one from the week before we bought the car with things like air filter/oil filter etc etc and although the oil was nice and clean the air filter had clearly not been changed for a while

- it was jet black.

Reply to
Coyoteboy

Is this a manual transmission? Usually gearbox oil changes are n't called for very frequently if at all (not that that means they don't need them)

Reply to
adder1969

Yes. Its supposed to have one (depending on which manual you read) at around 56K miles. Its used fairly heavily and when i dropped the box oil (while doing LH driveshaft replacement) the oil was as black as soot and contained some small metal flakes from the occasional grind from the previous owner im guessing. It was definitely time to change it and its improved shifting noticably so all's good. IIRC its in the maintenance schedule for the car at 56K (?) and the car just hit 92, the previous owner had it til 76K and my cars box ('91 celica GT4) hasnt blackened, more than a tint, its oil in 20ks worth of driving and its supposed to be changed every 32K - hence my estimation that they have never changed it. Their garage was a complete rip-off merchant, as ive found with every garage ive had the displeasure of dealing with, hence always DIYing and following maintenance schedules myself. Still, good result, just got the other shaft to do now, fortunately no oil drop needed there.

Reply to
Coyoteboy

With 75W-90, you might start to experience shifting problems in winter with a cold gearbox. If so, you might be able to find something like Motul Motylgear 75W-80 to try.

Many cars are very fussy about their transmission oil when it comes to good shifting.

Commenting on other posts, I've seen ATF go black when used for a long time in a manual box. It's certainly not the best for long gear life, but it can sometimes be the best oil for cold shifting. It deteriorates quickly and needs replacing more often than proper manual oil. You'll always end up with metal flakes in the oil anyway.

GL4 oils are generally recommended for FWD cars without hypoid diffs. GL5 (extreme pressure) oils can be more corrosive of brass components. Motul (among others) claim their GL 4/5 oils aren't corrosive.

John

Reply to
John Henderson

I was under the impression, rom a good oily friend of mine, that these were viscosity ratings at specific operating temperatures. The first is the MAXIMUM viscosity (minimum flow characteristics) at 0 degrees C and the second is the maximum viscosity (min flow rate) at 100C.

This would suggest that a 75/80 and a 75-90 would have the same characteristics at any start-up temperature as these are standardised flow rates used throughout industry. The upper end is the end that is affected, and the gradient between, so while the box oil gets to its max, say 100 for arguments sake, the 75/80 will be less viscous than the 75/90 at the same temp. So ultimately the only thing that would cause notchy cold-weather issues is choosing an oil with a different lower limit as this is whats effective at cold temps.

J

I threw ATF in my celicas box, a known modification for a little less loss considering a very similar manual box from toyota uses it as standard, but it has killed my synchros in 12 months - time for a box rebuild. Wont be doing that again.

Its the corrosivity that im worried about but i was assured by several retailers that it would be fine if it was recommended in their books.

Reply to
Coyoteboy

I'm no expert, but I understand there's a lot of scope for variation in the standards. Figures I've got for viscosity at

100ºC for 75W-90 gear oils show a range from 14.2 (Motul Gear 300) to 18.5 (Castrol Syntrans M). I don't have figures for 0ºC in front of me, but I'm sure there'll be significant differences. And I'd expect those to stand out more when comparing a 75W-80 against a 75W-90. Certainly the differences between two viscosity grades at 40ºC can be dramatic (eg 107.8 for Motylgear 75W-90 vs 58.8 for Motylgear 75W-80).

And of course there's a lot more to ease of shifting than just the viscosity.

I'd hope so, but it boils down to what's acceptable to you vs what's acceptable to the oil manufacturer. I recall reading that the long-term difference in syncro wear due to corrosion by EP additives is about double from best oil to worst.

John

Reply to
John Henderson

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.