gearbox question

[pfenlon]

I put my 15K mile TR7 away about 4 months ago, after getting an MOT and having SU carbs fitted etc etc.

I had it advertised but it didn't sell.

Last week A prospective buyer caused me to extract the car from its hibernation and after charging the battery I

went to get some fuel, the gearbox initially was Stiff when engaging first to second, thinking that it was just

the oil which needed a warm up, which after a few miles it did get easier, but still not perfect which it was before I put it away.

There was no sign of an oil leak under the 5 speed box either, puzzling???

The buyer didn't buy the car for the paintwork wasn't shiny enough, I did point out that it was the original 1980 paint, but he told me that with only

15K miles it should look like it came out of the showroom, I didn't argue.

[Cobber]

There are 4 rubber bushes part# UKC 854 on the gearbox these may have perished, poly ones are available.
The mounting rubber may also have perished.

[pfenlon]

the rubbers you mention just weren't there when I bought the car, and gear change was "different" but after renewing them the gear change was fine.

I can't understand whats changed I will check the oil level after the frosts have buggered off.

[busheytrader]

Hi,

Any idea what oil is in your gearbox? By modern standards the change between 1st and second in the 5 speed box can be stiff from cold, even more so if too viscous an oil is in it. I made this mistake and 2nd became almost impossible to select. I flushed the box out and changed over to MTF as used in the latest Mini gearboxes. The gearchanges became slick and easy, although 1st to 2nd cannot be rushed when starting out on a very cold morning.

If you're in a part of the world that is frosty, the cold temps and too thick a grade oil could be the problem.

Adam

[Sautie]

This is a long answer but was written by Nols Pienaar for the South African Club magazine Sabrina in September last year.

ALTERNATIVE GEARBOX LUBRICATION FOR TR7/8

My friend and fellow club member who lives in Germany, Gertjan van de Klashorst, owns a beautiful black TR3B as well as a very nice metallic blue TR7 drophead, known as Blauboet. Some time ago he sent me an email in order to find out if I knew why Blauboet's gearbox appeared to become a little hot on long trips and what gearbox oil should be used.
The owner's handbook of his car, a 1980 model from Canley with five speed box, specified GL4 Hypoid 80 gear oil. I said that I am using ATF because that is what British Leyland (BL) specified for five speed boxes for 1980/81 cars.
Gertjan then proceeded to investigate the matter and ended up communicating with Alec Pringle, an experienced person in the technical department of the TR Register in the UK. In response to Gertjan's questions, Alec answered as follows (Gertjan gave permission to share this information):
"Back in the 1970s there was much confusion at BL about the 5-speed LT77 gearbox. Two problems, first problem difficulty / engaging gear from cold start especially in winter, and second problem the gearbox overheating in hot summer weather. So BL stopped using Hypoid 80 and switched to ATF - which 'improved' both problems, or at least alleviated the symptoms, but at the expense of premature gearbox wear / failure. All BL cared about was easy gear changing for the first year - what happened afterwards was not their problem, the car was out of warranty..."
"The solution that I have preferred for the past 10 years was recommended by the late Ken Tomlinson. He was the BL transmission wizard back in the day, and was responsible for most of the competition and development transmission work in the 1970s and 80s. Very fine craftsman.
Later he maintained all the transmission for the ex-works TR7V8s, and other competition cars. The gearbox oil recommended by Ken was MOTUL GEAR 300 - see link."
https:www.motul.com/gb/en/products/oils-lubricants/gear-300-75w90?f%5Bapplication%5D=141&f%5Brange%5D=25
"It is good for gearbox and rear axle alike, but for limited slip diffs use the GEAR 300 LS."
Gertjan also questioned him about the use of Liqui Moly, to which Alec replied as follows:
"Liqui Moly is decent stuff for many applications, but it does NOT seem to suit the LT77 gearbox - quite the opposite in fact. No, I don't know why that should be, I speak from practical experience with TR7 and SD1 gearboxes, I don't know the theory!"
"If this was my gearbox, I would drain what is in there.
Then refill with ordinary ATF, old-fashioned Dexron 1 or Dexron 2 specification - NOT any of the more modern 'enhanced' ATF fluids. Drive maybe 10 kms, to get the box warm, and drain again, and let the ATF drain fully - this should remove the last of the Hypoid 80 and Liqui Moly, old fashioned ATF is a good flushing oil!"
" Now finally refill with GEAR 300 - which is a very long lasting oil. Remember to check level after driving the car 1 or 2 kms."
I myself will try this recommended lubricant. I noticed that it is fully synthetic and saw 1 litre containers on the shelves at Midas nearest to my home (Elardus Park) and noted that it was quite expensive at more than R200 per container. On the other hand, if it will help to prolong the life of my TR7's gearbox it may be worth it. Far cheaper than a gearbox rebuild!
Nols

[saabfast]

Interesting that is fully synthetic as you note. I thought these gearboxes needed mineral and had been looking at various mineral MTF's. I currently use the ATF recommended handbook for my '81 car which IIRC is a Ford spec ATF rather than Dexron, although probably not as critical in a manual box. The change is OK now but sometimes a little slow to avoid a slight crunch, but as improvements had been reported with MTF I thought it might be worth trying.

[Hasbeen]

I changed the 7 from ATF to MTF about a year ago.

About the only difference if any was that I thought the box ran a little quitter. It could have been fact, or wishful thinking, after mucking around flushing the box during the change.

Hasbeen

[dursleyman]

This has to be one of the most discussed topics on the Forum and everyone has their favourite.

Like Sautie has added earlier, BL realised they had a problem and so recommended the ATF which was the easiest/best option available at the time, but things have moved on a lot in the past 30 years. Their gearbox guru found that the Motul 300 MTF worked better and so he recommended it in the rally cars. The other one highly thought of is the Pennzoil/GM Synchromesh and I find this stuff works pretty well myself. The Motul 300 is currently £14.49 per litre and the Pennzoil is £15.90 per US quart on Ebay.

.

[TR Tony]

I have the Motul 300 in my TR8 gearbox & it certainly improved the gearchange. It is however still quite stiff from 1st to 2nd when cold, fine when warmed up.

Castrol Syntrans (previously called SMX) is also very good. I have that in my TR7 gearbox (late car) & even from cold 1st to 2nd gear shifts are smooth.

[timcar]

I tried ATF but found the gearbox much noisier, then I read on one forum about Redline MTL 75/80.
This is a modern synthetic oil but is safe for brass synchros. It's quite expensive but have used it for 1 year, 3,000 miles and found that shifting 1st to 2nd when cold is almost perfect, and much quieter than ATF.

[FI Spyder]

When I picked my car up in Sacramento it was 90F out and stayed that way to near the Canadian border. Overnight it dropped to 65F and spotty rain. I got my first wiff of the 1st to 2nd gear change with the original stuff that was in there. I changed to Pennzoil after reading about it on this forum but bought the synthetic thinking it would be better. It was better than the stuff in there but still double clutched when cold. The following year I changed to Pennzoil MTF. Problem gone but still shift careful (talking about 100,000 miles here). I paid about $7.95 Cdn quart/litre. After two years I changed it again and the price was up to $12.95 (from the same place). That being said if you do the currency conversion somebody in the UK is importing it in a private jet.