Subject: [TR] Synthetic gear oil

From: [email-masked]
Date: Fri, 20 Dec 2013 20:25:00 -0600

Hello List,

Does anyone use synthetic gear oil in the transmission and/or differential of
their TRs?  Any comments on the pros and cons of using synthetic oil?
Thanks.

John DeLuca
1965 TR4A in restoration

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From: "Randall" <[email-masked]>
Date: Fri, 20 Dec 2013 20:28:09 -0800

> their TRs?  Any comments on the pros and cons of using synthetic oil?

I've been using Valvoline full synthetic gear oil in all my Triumph diffs for a long time.  The diff in my 59 TR3A was already well
worn when it came to me in 1984.  20 years and perhaps 200,000 miles later, it wasn't any worse.  ISTR I changed the pinion seal
once, but otherwise it was still working fine when the car got wrecked.

More recently, I switched to using Redline MT-90 in the transmissions and overdrives.  It improved the synchro action, and so far no
problems, at least not that I attribute to the oil.  I have had a few failures, but they clearly had other causes.

But I wouldn't use a synthetic in the transmission that wasn't designed for a synchronized transmission.  Reportedly some of the
gear oils on the market are too slick and interfere with synchro operation (which requires a certain level of metal-to-metal
friction).

Only "con" I see is increased cost.  The MT-90 in particular is worth shopping around for, as prices vary quite a bit.  Compared to
the cost of new synchro rings, it's a bargain.

Randall

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From: Tony Drews <[email-masked]> {sentby:smtp auth 173.20.105.192 authed with [email-masked]}
Date: Sat, 21 Dec 2013 15:55:57 -0600

I've had a long series of e-mail conversations with Steve Yott who 
knows more about our trannies than most of us have forgotten.  He did 
some testing where he had a window into the gearbox to see what was 
happening.  One think I wasn't aware of is that different lubricants 
"foam up" more than others.  He strongly recommends the Redline MT90 
- it foams less and is compatible with the synchros and 
overdrive.  When the lubricant foams up it doesn't lubricate as well.

So, another vote for Redline MT90.  As infrequently as the lubricant 
gets changed in the tranny, the ~$15 per quart is cheap insurance.

Cheers, Tony

At 10:28 PM 12/20/2013, Randall wrote:
>I've been using Valvoline full synthetic gear oil in all my Triumph 
>diffs for a long time.  The diff in my 59 TR3A was already well
>worn when it came to me in 1984.  20 years and perhaps 200,000 miles 
>later, it wasn't any worse.  ISTR I changed the pinion seal
>More recently, I switched to using Redline MT-90 in the 
>transmissions and overdrives.  It improved the synchro action, and so far no
>problems, at least not that I attribute to the oil.  I have had a 
>few failures, but they clearly had other causes.
>
>But I wouldn't use a synthetic in the transmission that wasn't 
>designed for a synchronized transmission.  Reportedly some of the
>gear oils on the market are too slick and interfere with synchro 
>operation (which requires a certain level of metal-to-metal
>friction).
>
>Only "con" I see is increased cost.  The MT-90 in particular is 
>worth shopping around for, as prices vary quite a bit.  Compared to

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From: Dean Tetterton <[email-masked]>
Date: Sat, 21 Dec 2013 17:26:36 -0500

Just before leaving for the VTR Convention in Hudson WI in 1998, I changed the
fluid in my TR6 A OD tranny to MTL. Drove to the convention from Richmond, VA.
by way of Canada and put on a lot of miles. Tranny is still working well and
have changed the MTL in it once. Would not use any thing else in my
transmissions. Also use it in all the race cars.

Happy Holidays
Dean Tetterton

On Dec 21, 2013, at 4:55 PM, Tony Drews wrote:

> I've had a long series of e-mail conversations with Steve Yott who knows
more about our trannies than most of us have forgotten.  He did some testing
where he had a window into the gearbox to see what was happening.  One think I
wasn't aware of is that different lubricants "foam up" more than others.  He
strongly recommends the Redline MT90 - it foams less and is compatible with
the synchros and overdrive.  When the lubricant foams up it doesn't lubricate
as well.
>
> So, another vote for Redline MT90.  As infrequently as the lubricant gets
changed in the tranny, the ~$15 per quart is cheap insurance.
>> I've been using Valvoline full synthetic gear oil in all my Triumph diffs
for a long time.  The diff in my 59 TR3A was already well
>> worn when it came to me in 1984.  20 years and perhaps 200,000 miles later,
it wasn't any worse.  ISTR I changed the pinion seal
>> More recently, I switched to using Redline MT-90 in the transmissions and
overdrives.  It improved the synchro action, and so far no
>> problems, at least not that I attribute to the oil.  I have had a few
failures, but they clearly had other causes.
>>
>> But I wouldn't use a synthetic in the transmission that wasn't designed for
a synchronized transmission.  Reportedly some of the
>> gear oils on the market are too slick and interfere with synchro operation
(which requires a certain level of metal-to-metal
>> friction).
>>
>> Only "con" I see is increased cost.  The MT-90 in particular is worth
shopping around for, as prices vary quite a bit.  Compared to
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From: marty <[email-masked]>
Date: Sun, 22 Dec 2013 19:21:41 -0500

Switched over to MT90 myself years ago per Redlines recommendations. I'm sold
on it also.

Marty

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> Date: Sat, 21 Dec 2013 15:55:57 -0600
> To: [email-masked]
> From: [email-masked]
> Subject: Re: [TR] Synthetic gear oil
>