Rear tyre- wear and sizes and gearbox oil

[Dave Guest]

Hi.
I'm looking for a litte infomation on the best tyre size for the rear on a lomax 223.
Having removed mine tonight there seems to be alot of wear on the drivers side. Is this normall on a three wheeler? The bearing feels fine.
The second question is gearbox oil. A bit of hunting around the net came up with the answer of a 'Hypod' non synthetic oil, but down at my local Halfords when I asked which one this was they looked at me as if i had just landed from the planet Zog.
Many thanks Dave

[Paul]

I'm using Halfords Gear Oil Part Synthetic, 79W/90 GL-5 gear oil. From memory, I think Citroen recommend EP80 gear oil. I can't remember where I found the source reference for the 79W/90 GL-5 gear oil; it could have been those little flip-charts that Halfords have on the front of their shelves. The gearbox seems quite happy on that. The box was a bit noisy before the I renewed the oil and the noise level remains the same, but nothing has got worse. However, geearboxes are pretty robust items.

With the tyre question, that could be down to numerous factors that affect the wheel alignment, e.g. unequal ride height from side to side, misalignment of the rear suspension, perhaps uneven weight distribution. I can't see that a different width tyre would correct, or cause wear on one side of the tyre. Just a thought, but if nothing else is obvious, you could check the rear wheel alignment by getting the car level (place plywood shims under the tyres if your garage floor is not level), then check that the rear wheel is perpendicular

[Ken Hanna]

As regards the type of gear oil for an A series gearbox, there's been quite a lot of discussion about this over the years and the general consensus seemed to be that GL-5 grade should be avoided, as the level of sulphur-based extreme pressure additives in GL-5 oils is too high and may attack the 'yellow metal' components in the synchromesh mechanisms.
Gl-4 oils are reported to have much less of these potentially harmful additives.

Also, there's not really any need for a 'hypoid' type oil, since the crownwheel and pinion set in an A series gearbox, albeit of spiral bevel design, has zero offset.
http://en.wikipedia.org/wiki/Spiral_bevel_gear

As regards the viscosity of the gear oil, straight 80 or 90, 75W90 or 80W90 all seem to work just fine...

Ken

Hi.
I'm looking for a litte infomation on the best tyre size for the rear on a lomax 223.
Having removed mine tonight there seems to be alot of wear on the drivers side. Is this normall on a three wheeler? The bearing feels fine.
The second question is gearbox oil. A bit of hunting around the net came up with the answer of a 'Hypod' non synthetic oil, but down at my local Halfords when I asked which one this was they looked at me as if i had just landed from the planet Zog.
Many thanks Dave

[Dave Guest]

Many thanks for all the infomation. I now know exactly what 'Hypoid' means. I'll search the shelves at my local Halford for a GL4 semi synthetic gear oil. Never had any joy with the flip chart things.
For the rear tyre I've ordered a cheap Toyo 135 rear from ECAS. Although a 125 was the original fittment I've no idea how long it's been on there so by throwing a cheap tyre(£35) on I can at least see how bad things are. It could just be that I'm a large framed chap (some who say fat) and I like to go around roundabouts as fast as I can.
Many thanks Dave

[notsmartcar]

I think you may find the wear on your old tyre occurred on the car it was on before of course I may be wrong.

[Mendip.Wursel]

I use 75w90 Hypoil oil for the gearbox and 135 tyres as they tend to be cheaper and more available than the 125's.

[Paul]

general consensus seemed to be that GL-5 grade should be avoided

Oh gawd! That means another oil change