Gear Oil

[Brightonuk]

I was looking to change out the gear oil in my T9 using Redline MT-90 and as suggested going in via the top of the gear lever

 

On removing the cover I can see the bowl is dry?

 

 

 

 

 

How much oil does should I add?

 

Thanks

[coffee break]

Look for a threaded metal plug on the side of the main case. Generally this type of plug is about a third the way up from the bottom of the case. Add gear oil until a little runs out the hole. I think this is SOP for most transmissions.

[Anker]

The trouble is that the plug is almost impossible to get to. It is up against the driver's footwell. I plan to drill a hole in the footwell side so I can get at the plug from there.

[Brightonuk]

The trouble is that the plug is almost impossible to get to. It is up against the driver's footwell. I plan to drill a hole in the footwell side so I can get at the plug from there.

1987 Caterham 1700 Supersprint

 

The drill a hole concept does not work for we as the frame rail is dead center over the plug

 

So if the car is level should I at least see oil in the housing as some have said they drain the oil from the top but I do see any sign of oil or how to access any oil that may be sitting in the housing.

I am sure I am missing something here

Edited January 6, 2021 by Brightonuk

[papak]

Don't fill through the shifter opening! You will just end up with a puddle on the floor. There is no passage into the tail shaft or main case from there. If you can, remove the top cover and weld a threaded bung into the right front corner (CAUTION! Do not move the shift lever while the top cover is off. You risk screwing up the synchronizers.). This serves as a fill port and once filled, you can calibrate a dipstick as well. Over the model years, the fill volume varied from .98 to 1.9 liters. According to Chris at BGH Geartech, 1.2-1.25 liter works best. At 1 liter, the gearbox tends to run a bit warm, especially in competition and with more than 1.25 liter, hot, expanding lube will work it's way past the shaft seals a bit. When I last had my gearbox out, I also welded a bung in the location of the vent hole (you need the underlying baffleing to ensure that you are just relieving pressure) and added an AN-3 vent line that runs forward about 12" and upward another 6". Bone dry gearbox exterior now.

[Brightonuk]

Thanks Mate saved me a lot of grief cause by ignorance going down the wrong path but is a bummer, I thought pull the lever fill from there it seemed so easy.

Your suggestion is for a future project.

 

Staying with this issue Plan #2 was cut down an Allen wrench and try to fit it into the nut but even if I get the plug out I do not see a way of getting the oil into the case.

 

Another question should I apply any grease to the shifter linkages?

[papak]

I use a bit of silicon brake grease. Chris advised to stay with the plastic shifter saddle. It is cheap to replace if it shows wear and last a long time anyway. I have heard of a couple of fellows using a hole saw to cut an access opening into the side of the transmission tunnel to gain access to the side plug. They are mounted in an elongated "boss". Earlier cases have the filler lower, later cases have it higher. The lower hole allows .98 liter, the higher 1.25 liter.you can get more in the lower hole by jacking up the drivers side of the car.

[Croc]

Plan #2 was cut down an Allen wrench and try to fit it into the nut but even if I get the plug out I do not see a way of getting the oil into the case.

 

The cut down allen key was how I did it on my last 2 T-9 cars and I know of others doing the same. Then it is a complete pain but you can do it with plastic tubing and a big syringe to suck out the old then inject the new to refill with fresh. This is similar to what I used - probably cheaper ones with some searching.

https://www.amazon.com/Lumax-LX-1387-Extractor-Dispenser-Capacity/dp/B0059HK5D6/ref=sr_1_11?_encoding=UTF8&c=ts&dchild=1&keywords=Garage+%26+Shop+Fluid+Evacuators&qid=1609925629&s=automotive&sr=1-11&ts_id=15707821

 

 

For oil level, the original production cars were filled until the oil was just at the level of the drain hole - just before starting to leak out. You should be able to do the same by testing with a small finger (or like me and waiting until it overflows ) as you will only suck about 80-85% of the oil out in this approach and will not need to refill the full recommended volume.

 

The other possible option is be lazy. The T-9 was designed by Ford to be sealed for life of car in original production and not touched. In our cars the clutch usually goes much earlier than life of car and so when you pull the engine to change the clutch you would change the transmission oil then.

[Anker]

If you take the cover off, which I have also considered, can you see the fill hole inside from the opening?

 

I like the idea of a bung and a home made dip stick.

[Brightonuk]

As I said the hole concept will not work as there is a structural frame bar right in front of the plug

 

Even with an allen cut down to a nub it is near impossible to get to.

 

I am going to wait on this and think if I wanna frustrate myself by attempting this, the car is running great and the oil change was just..........................well because I thought it was a good idea (and I purchased the MT-90)

 

Thanks Croc that looks like a option if I commit .

[11Budlite]

I ended up modifying the T9 I had in my old Birkin so I could fill and check the level from above. Here's a link to an old thread and some photos: https://www.usa7s.net/vb/showthread.php?2765-T9-Trans-Cover-Fill-Plug

[papak]

With a flashlight and patience, you can locate the fill hole with the cover off. You might try one of the inexpensive iPhone boroscopes. As Croc said, Ford designed these gearboxes to be lubed for life. While you may experience an eventual input or output shaft seep, it will most likely not prove significant.

[papak]

 

Finally had enough time to dig out a couple of pics (sorry but my editing skills are a work in progress). In the first one, a cutaway view of the tail shaft, it is obvious that the shifter enclosure is a dry area. In the second picture, the sheetmetal alignment bracket for the selector shaft "locking ring" (more accurately the reverse selector ring) is to be seen attached to the bottom of the top cover. A circular bump with a 1/16" vent hole is located immediately above this bracket. This location prevents gear oil from being slung out under operation. This invariably coats the top of the cover with a fine mist of gear lube over time (apparently an essential component of Ford's anticorrosion program). If you should choose to install a proper vent line, mounting the necessary bung in this bump-out serves to allow only pressure, not mist to enter the vent line.