Gear box

busheytrader · Postby **busheytrader** » 12 Mar 2008 08:56

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Mildred

We are very happy with this conversion as it has transformed the car to what it should have been some 32 years ago. We will keep you posted as the results of the gearbox oil analysis.

Mildred Hargis
<hr height="1" noshade id="quote"></blockquote id="quote">

From what I've read many times about the 5 speed 7 / SD1 box it was a top up item and not a drain and refill at service intervals. Additionally the ATF may have helped the gearchange but offered lower protection which wasn't discovered by the owner until well out of warranty. It'll be interesting to see how your box and oil stands up.

Cheers,

Adam

TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, Single Pipe Exh, 3.08 Rear, 200lb Spax & Solid Bushes, Anti- Dive, Granada Vented Discs & Calipers, AllyCat 5 Spokes. No Door Stickers.

calex59 · Postby **calex59** » 13 Mar 2008 16:19

For what it's worth, most american cars use ATF in the manual transmissions and have for quite some time now. I have a 1994 Ford Ranger 4WD 5sd manual transmission pickup and it uses ATF, with 160,000 miles on it the transmission shows no signs of wear and the oil was only changed once after 110,000 because some little rubber seals on top of the transmission started leaking and needed to be changed out. I see no reason for the 5sp box that is on my 1980 TR7 to wear any more with ATF than do the American cars. However, as soon as I can get my hands on some(it is hard to find in my area for some reason), I am going to change to Pennz oil synchromesh MTF, just to be on the safe side. I know one thing for sure, my car shifts so much better with the ATF in it.

krewat · Postby **krewat** » 14 Mar 2008 14:15

I did the ATF change once on a 5-speed I rebuilt.

I was building a '75, using '78 tranny and rear. I took a known-good 5-speed tranny, opened it up, replaced all the wear parts I could find (bearings, thrust washers, syncros, etc) including the oil pump and that funky sleeve that allows gear oil to flow into the output shaft.

Put 75w90 gear oil in it, and it was perfect. Some cold mornings where the gear oil was too thick for the synchros (especially 2nd), and made me think about it for a while, do some research and found that ATF was recommended later on.

So, I tried it. WRONG.

Thing made a lot of gear noise, and the syncros, well forget it. They grabbed so fast that when stepping on the clutch and immediately putting it in gear, the car shook from the output shaft (and driveshaft) taking the inertia of the input shaft and cluster-gear (laygear).

Anyway, beware the ATF thing.

I've rebuilt three of those 5-speed gearboxes, one was so bad the bearing had welded onto the cluster gear.

Never had an issue with 75W90, from temps ranging from around 10-20 degrees F, to the high 90's.

The only thing I worry about is stripping out the oil pump gears when it's too cold out.

But even straight 50 was too thin overall.

I always thought about putting an oil pressure gauge on that tranny - because you don't know the oil pump is gone until the thing welds itself together [:D]

Workshop Help · Postby **Workshop Help** » 14 Mar 2008 17:30

Here we go again! This is starting to remind me of the Monday night WWE RAW 3-way steel cage match.

To throw another wrench into the works, is there an opinion out there about Mystic 75w-80 gear oil?

I just get more confused every day.

Mildred Hargis

calex59 · Postby **calex59** » 14 Mar 2008 18:50

<blockquote id="quote">quote:<hr height="1" noshade id="quote">To throw another wrench into the works, is there an opinion out there about Mystic 75w-80 gear oil?

I just get more confused every day.<hr height="1" noshade id="quote"></blockquote id="quote">

I know, I am almost sorry I started this thread. You read where you should change to ATF, or MTF, and then are told by half the people on here that it is better to stay with the 75W although the reason for changing to ATF to start with was because the 75W was to heavy and burned up the gear box because the oil pump wouldn't funtion with it. Sigh.

Odd · Postby **Odd** » 14 Mar 2008 19:38

<blockquote id="quote">quote:<hr height="1" noshade id="quote">For what it's worth, most american cars use ATF in the manual transmissions and have for quite some time now. <hr height="1" noshade id="quote"></blockquote id="quote">

Well, as far as I know both the T56 and the Tremec TKO600 state that it's the GM Liquid Gold* you're supposed to use...
/Odd
(Personally I wouldn't put anything else into a LT77 or a R380. Ever!)

*
"GM Goodwrench Synchromesh Transmission Fluid" (part # 1#12345349) or
"GM Vehicle care Synchromesh Transmission Fluid" (part # 1#10953465)

Beans · Postby **Beans** » 14 Mar 2008 23:18

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Mildred

... Monday night WWE RAW 3-way steel cage match ...Mystic 75w-80 gear oil<hr height="1" noshade id="quote"></blockquote id="quote">
Mystical indeed, I'll stick to Castrol SMX-S synthetic gear oil with a viscosity of SAE 75W-85 [8)]
It even got my R380 'box to behave a little bit.

<center>

1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (not very well known yet, but back on the road)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC
http://tr7beans.blogspot.com/</center>

johndillingham · Postby **johndillingham** » 15 Mar 2008 00:36

This TR is my 4th LT77. First and second were in an SD1 Rover V8, next was in a Range Rover Vogue. The first one failed in the SD1 when the pump self destructed. Left with only 4th. Got a used one from a TR and all went well. Refilled with Dexron and it behaved fine until I sold it. I'll be putting something other than gear oil in this one, and see if any damage has been done. Great thread, thanks!

Cheers!!
John Dillingham
Canton, Georgia
parliament.scout@yahoo.co.uk.
visit me at www.cherokee-pca.org and fit4life.wholefoodfarmacy.com

calex59 · Postby **calex59** » 15 Mar 2008 02:14

So, one more question. Is it ok to use Pennzoil synchronous manual transmission fluid or should I go back to 75w, this time in a synthetic? I do not want to burn up the transmission, it is in excellent shape and if I have to put up with hard shifting when it is cold, so be it. Is there a consensus on what should be run in these 5sp boxes?

Odd · Postby **Odd** » 15 Mar 2008 03:18

There's no consensus on what to use - apart from the fact most conscious people (and the Leyland
factory recommendations) stay well clear of hypoid gear oils. The fluid to use is either the GM Liquid
Gold listed above or the Pennzoil MTF (which is the same as the GM stuff but slightly less pricey).
There are some other brands of MTF used in some late LR vehicles that probably would be equally
useable. Some diehards still stick with the Leyland stop-gap solution; ATF - but why use it now when
there's proper MTF on the market..?

calex59 · Postby **calex59** » 15 Mar 2008 03:25

<blockquote id="quote">quote:<hr height="1" noshade id="quote">There are some other brands of MTF used in some late LR vehicles that probably would be equally
useable. Some diehards still stick with the Leyland stop-gap solution; ATF - but why use it now when
there's proper MTF on the market..?<hr height="1" noshade id="quote"></blockquote id="quote">

Thank you, that is a clear and concise answer to my question. I have ATF in mine right now, but will change to MTF as soon as I can get it. For some reason the parts stores in this part of California don't carry it, but I have found it online and ordered two quarts of the Pennzoil MTF. 9 Bucks per quart but it should do the trick. Thanks again.

FI Spyder · Postby **FI Spyder** » 16 Mar 2008 02:15

If going to MTF only consider the synthetic. See bottom of the page. I believe I paid about $12 per litre after my Old English Car Club discount. It's the synthetic that gives better low temp. sifting.

http://www.pennzoil.com/products/gear_oil/index.html#syn_gear7590

When I picked up my car in Sacramento in the beginning of June it was in the high 80's into the 90's. I had no trouble shifting the car hot or cold. It's easy to see why no one here worried about what oil was in the transmission. On the third day at the Washington State/Canadian border with the temperature a more sane 75 with showers emminent I encountered the dreaded second gear balk. I changed to the Synth I believe it was the GL5. There is a difference now. Do not use the standard gearlube. Make sure it's the synth.

TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

calex59 · Postby **calex59** » 16 Mar 2008 10:35

Synthetic it is, thanks for the info. I live near Sac, and it does get hot in the summer but it also gets quite cold in the winter with occasional snow. I like the way it shifts with the ATF but understand, from several comments, that it doesn't lube as well, so I will change to the synthetic MTF, thanks to all on this thread and if anyone else has something to add please jump in.

Underdog · Postby **Underdog** » 16 Mar 2008 12:39

For what it's worth, most american cars use ATF in the manual transmissions and have for quite some time now.

Also FWIW, Chrysler specified ATF some years ago in manual boxes. I've been running it in the MGB OD box for over 10 years now. Another story but I was having problems with the unidirectional clutch slipping with the specified 20/50 motor oil.
If you think about it, an automatic trans has tiny planetary gear sets in comparision to a manual box. So I don't think the lubricating or load bearing ability of ATF would be inferior. Having said that, I've been using the GM stuff in the 8. I have a wholesale GM accout with my shop so it helps with the price

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.

bmcecosse · Postby **bmcecosse** » 08 Apr 2008 18:40

After researching various ATF oils in the UK - i'm filling my 5 speed box with Castrol 10W 40 engine oil! It seems to be higher spec than the ATF - and v much less expensive.

Anonymous

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