A-Type Overdrive Overhauling - Part 9 - The Final Test

[@mikeg5877]

Elin, you are both an excellent mechanic and an EDUCATOR... well done series

[@glenroger]

Great job. I might have the nerve to tackle my overdrive problem with all the knowledge I've gained from your videos. I love to see your determination to solve the problems and your innovative solutions and hacks. Mine doesn't come out of overdrive properly. I'm going to check the check valve and redo the adjustments before I resort to tearing it all down. Thanks!

[@andypaine7489]

Elin great video, as always. I wanted to second your use of ND30 wt. I’m not an engineer, but I can attest it worked great for me. After buying my TR-6 (w/J type OD) I changed all the fluids and filled the transmission with 80/90 wt like the manual says. From that point until last month, the OD would lock to the engaged position after driving about 45 minutes. I cleaned all of the filters, rechecked the fluid levels, I even changed the relay and nothing fixed the problem. Then I got a tip from ChefTush about ND30 wt- made all the difference in the world. In fact my wife and I just drove it to the FL Keys and on the 800 mile round trip the overdrive worked flawlessly.

[@RustyBeauties]

After I read that article I don't worry anymore about the type of oil. When there are many different opinions about something I assume all sides have their plusses and minuses.... Anyways I am happy I used nondetergent, because it tastes better :) You will see in my next video what I am talking about LOL

[@funonutube100]

Congrats Elin after all your hard work great to see it performs perfectly!!!!

[@RustyBeauties]

Thanks Gord!

[@SendingStache]

its been awesome to see your progress on this!

[@paulx5358]

Hi There, very impressed with your video. I have a TR6 USA left hand drive Aug 1974 Type A gearbox with overdrive. I'm having alot of trouble trying to wire up the gearbox. Is there a wiring diagram you can recommend to help. Many thanks Paul

[@RustyBeauties]

Hey Paul, I have multiple videos on wiring an A-type overdrive. This is an old one, but I think it explains it best. The wiring diagram starts at around 7:50 kzbin.info/www/bejne/oYGxanuAnbqYpc0 This is the factory diagram www.advanceautowire.com/tr2506.pdf Have in mind that the TR250 and TR6 from 69 to 71 had an optional A-type and 72 and after had an optional J-type, which is wired differently. So even though your car is 74, since someone installed an A-type check the diagram for the early cars 69 to 71

[@chumbuddy100]

I think also that the viscosity difference between SAE 30 and 80W90 gear oil can make a difference in the pressure also. It looks like there is a pressure bypass working in the circuit too. I would make the adjustments to bring the pressure into the spec operating range.

[@RustyBeauties]

I will wait till the balls come and change them, maybe that will give me better results. I actually tested another unit today, which had 80W90 inside and it had the exact same pressure. Of course there no guarantee there wasn't something else causing the lower pressure there, but I also read couple of internet posts and I find that generally people have pressure between 310 and 350 psi. I will decide what to do later. Need some sleep now LOL

[@stevewarren6336]

In reality there is little difference between in the viscosity with an SAE30 verses a75w or 85w gear oil or an iso100 oil . The way the classification work is that oils loose viscosity as they heat up. if you search for a Viscosity Comparison Chart you will see what i mean. Using an engine oil in gearboxes means that you loose out on EP additives and the load carrying properties gear oils contain . These additives 'don't cause problems with the O/D clutch and contrary to some opinions , they don't attack the syncro cones or the bushes. i have run a 75w/90 GL 5 oil for 20,000mls in a TR3A and when i stripped the box the oil was tested and the wear metal were low, though there was some shear down of the VI improver which happens with multigrade gear oils hope this helps

[@robertthornhill4379]

hi elin having watched you video on gear boxes they are not the dark art to take apart or repair like i was led to believe from bob in the uk 10/10

[@RustyBeauties]

I think someone is making it look too complicated on purpose :)

[@ralphcap2476]

Wow awesome work can't wait for the finally

[@RustyBeauties]

Thanks!

[@johnlille2544]

Elin....Kudos to you! JL

[@RustyBeauties]

Hey, John, your tool and pieces of advice helped a lot! Thank you!

[@ericgeisen4090]

Congratulations! Fantastic job -;)

[@RustyBeauties]

Thank you!

[@cheftush]

I think your pressure is very similar to mine? Excellent job.

[@RustyBeauties]

Exactly the same actually. So if it is OK for you it is OK for me :)

[@DavidPlass]

I'm confused. Did I miss the part where my wheels make my transmission move?

[@RustyBeauties]

Haha! You missed it yes! Well that is an easy way to test the OD. No matter which direction you use it it should be working. And for the record, there are many conditions when your wheels turn your transmission - like every time you lift your foot off the accelerator pedal while the vehicle is in motion for example.

[@DavidPlass]

Seriously, though, is it safe to drive the transmission from the output shaft?

[@RustyBeauties]

Absolutely. What do you think is happening when you are downshifting to stop? You are driving the transmission from the output. That is why the overdrive has 2 clutches. The unidirectional clutch releases when the output spins faster than the annulus. Think about that. When you are in neutral and raise the RPM they drop as soon as you lift your foot off the pedal, right. While driving though, when you lift your foot off the pedal the RPM stay the same and very slowly drop. Why is that? Because the wheels are turning your transmission and your engine...

[@DavidPlass]

Hm. Never having driven a car with manual transmission, I never thought about it.

[@cheftush]

First!

[@RustyBeauties]

First and reverse are not of interest here, only 2nd, third an fourth :)