Gearbox oil

[steveww]

Time to change the oil in the gearbox. I remember a number of people on this forum recommending a Redline product. Which one should I use for the 4 speed box?

[rgh0]

Hi Steve

Redline MTL is what I use

Rohan

[lotusdelta]

I second Rohan,
I recently replaced my gearbox oil with redline MTL...works just fine
David

[Emma-Knight]

My gearbox is quite noisy - so I'll have to change/refill oil too.
What about slick 50 to add?

Anna

[steveww]

Thanks for the info. I have ordered some MTL from Demon Tweeks

[oldokie]

I don't think Slick50 will quiet it down, but it might keep it from getting worse. I never had much faith in that sort of product until I put some Prolong in a friend's 59 Ranchero, figured it was like 'chicken soup' (couldn't hurt), any way, she blew a plug out of the head and ran that poor old 292 until it was so hot it stalled, had it towed home, I replaced the plug, filled the rad, and expected it to turn about 4000 on the starter, but it fired up, the rings no worse for wear!! Shocked me!!

[CBUEB1771]

A couple of weeks ago I contacted Red Line directly on this question. Their application engineers recommend 75W90NS for the EnFo 4 speed gearbox. This is an EP oil specifically formulated for good synchronizer performance. I had previously used Red Line's Light Weight Gear Oil without realizing that it contains a friction modifier that lessens synchro performance. There was no damage but I must say the deterioration in synchro performance was noticeable. Red Line's web site has quite a bit of information plus a spot to post your queries to the application engineers. It took a day or two for them to respond.

[rgh0]

Hi Russ

The original oil specification for the Ford box was 80 weight gear oil. Gear oil specs have come a long way in the last 40 years but the basic viscosity rating when hot should not need to be changed

Redline MTL is a 75W80 weight GL4 oil and is the best match from the Redline product line. The 75W is a cold viscosity measure and the 80 is the hot viscosity measure. Gl4 oils are intended for use in normal helical or spur gear applications. The MTL ( Manual Transmission Lube) is specifically formulated for best syncro performance and life

Redline also make a MT-90 GL4 oil but the box does not need an oil that heavy this is typically used in heavier duty gear boxes such as my Landcruiser.

The oil the Redline technican I think incorrectly recommend ( 75W90 NS) is a GL5 oil primarily intended for use in diffs and transaxles where a GL5 oil is required due to hypoid gear use in the differential. A GL5 oil is not required in the Ford box and can be detrimental to the life of brass syncro rings due to the sulphur content which is required to give it the Gl5 antiscuff rating. Having said that the Redline GL5 oils use less sulphur than most other Gl5 oils due to superior polyol ester base stock and thus it probably OK to use but it is in my opionion not the correct selection for our gearbox. Did the techncian explain why MTL which is the obvious choice was not recommended ? If you dont use MTL in the classic ford 4 speed box i dont know what gear box you would use it in and why do they bother making it !

Incidently when I checked with them about 4 years ago they recommended MTL to me which was what I expected.


cheers
Rohan.

[john.p.clegg]

nd what about the lotus (austin Maxi) five speed box?
It needs all the help it can get...

John

[rgh0]

Redline MTL in the 5 speed Lotus box made a signficant imporvement to the gear change especially when cold in my plus 2

Rohan

[Foxie]

Steve,

I use Castrol Driveline Syntrax 75W-90, API GL4/GL5. Widely available in this part of the world. Recommended to me by Lotus gearbox specialist Graham Boulton, Norfolk many years ago.

Sean Murray

[CBUEB1771]

Rohan,
Thanks for your detailed response. The fellow at Red Line didn't mention MTL at all in his response. I am still putting the gearbox back together and have only used the 75W90 NS as an assembly lubricant so I have time to rethink this. I'll use this as an opportunity to ask about snap rings for the main shaft again as nobody responded to my previous post. I have the late type gearbox with snap ring location for the ball bearing and speedo drive gear, as opposed to the earlier draw nut configuration. The Lotus parts book appears not to have been revised to reflect this change and these two snap rings are not listed. The US parts suppliers don't seem to know what I am talking about. The grooves for them seem to have the same dimensions as that at the front end for retaining the 3/4 synchro hub. Is the 3/4 hub snap ring (105E7059B) supposed to be used in the other two locations at the back end of the main shaft?
Regards

Hi Russ


Did the techncian explain why MTL which is the obvious choice was not recommended ?

Incidently when I checked with them about 4 years ago they recommended MTL to me which was what I expected.


cheers
Rohan.

[CBUEB1771]

Rohan,
I downloaded some technical articles from Red Line's web site. These documents clearly support your recommendation for MTL as opposed to their engineer's advice to me. Thanks for raising my attention.

[rgh0]

Hi Russ

When I fitted the Quaiffe gear set in my Elan the parts supplied replaced the draw nut syle shaft with a snap ring style one. I recall I used a couple of standard circlips to locate the speedo drive gear as 2 of these together fitted the groove width perfectly.

However I dont know if this part of the Quaiffe shaft is identical to the orginal Ford snap ring shaft but I suspect it is

regards
Rohan

[steveww]

Had chance to put some more miles on the Elan after changing the gearbox oil. What can I say? I am a Redline convert I was thinking that the box was due for a rebuild but the Redline MTL has made the box like new again, the shift is so much smoother. This has got to be one of the best value upgrades you can do.

PS - Not connected with Redline in any way except very happy with their product.

What Redline oil should I use for the differential and engine?