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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Sierra Gearbox

I am responding to the discussion relating to the gearbox oil specification.
It is my intention to fit a type 9 gearbox to my MGA which is in the process of a ground up rebuild.
However, I am aware that in South Africa, this gearbox experienced rear bearing problems under load conditions as it was used in a unique to SA, Cortina based LDV. Ford apparently solved this problem by driving the development of a fully synthetic GL5 75W90 gearbox oil. Hence the Ford packaged product for which the specs are difficult to identify.
I was fortunate enough to meet an experienced ex Shell lubricant representative who gave me this infomation.
While not readily available off the shelf in SA, GL5 is readily available on special order from a number of the reputable oil companies.
Spares outlets try to pass off normal mineral based GL4 & semi synthetic GL4/GL5 as adequate. Apparently not, according to my source, who is regularly consulted by the performance industry experts.
Internationally, GL5 should be available from most, if not all, the reputable oil companies.
I cannot comment on the capacity issue, except to speculate as follows: High capacity was specified to flood the rear bearing with the lower spec oil & reduce risk of failure. Lower capacity is within design parameters and is adequate with superior quality oil. A change in case design/capacity is also possible, but unlikely, unless dictated by a revised use/application.
Derek Martin

derek,thanks for your response.i could not come up with a conclusion.but as with you i think a 75w90 full
syn fluid will be spot on.i did learn that this trans
had a update later on for a different tailhousing,maybe for better/more fluid luberacation..
but i think if the correct spcified fluid is as easy to get by just going to a ford dealer and purchase,,well thats what i will do..cc
c.callaway

This thread was discussed between 08/07/2006 and 10/07/2006

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.