Hello, time for another stupid question. I was going to drain the oil on my transmission and differential this weekend since I was changing the shifter seal, backup switch and shift coupler. In all my manuals they show a drain plug on the transmission and the differential. On my car there is a flat boss where the differential drain plug should be and I cannot find anything on the transmission. The car in question is a 1964 Monza, 110, 4-speed car.

Am I missing something or were some cars made without drain plugs? Or is there some other way to drain the oil? Outside of siphoning out the oil I do not know what to do.

I can post pictures of where the drain plugs should be and what is on my car.


Keith

Keith
64 Monza Convert 110 4-speed
69 911T (IROC Clone)
"Horizontally Opposed"
05 GTO 6-speed (Gotta have a V8)
Chicago Burbs; the Anti-Dragon... 11 turns in 318 miles

After 1963 the drain plugs were left out of all stick trans and diffs and pg diffs too.

There have been tech tips written about drilling and tapping the bottom of the diff but that is iffy, not much ground clearance. If the diff was apart you could drill and tap the boss for a drain plug but not in the car, the casting is about an inch thick right there.

The typical way is to use a suction gun to pull the old gear lube out. Remember not to overfill when you are done.

If it is any consolation, you won't lose hardly any gear lube when replacing the seal and the backup light switch if you are quick to screw the new switch in place. Removing the seal won't cause much to pour out either.

Best, Steve

Wouldn't most of the gear lube drain out when the backup light switch is removed?

David Clamp


1965 Corsa convertible - 140 4spd/3.55/AM-FM

2013 Mustang GT convertible - 5.0, 6spd auto, Procharger i-1

2003 Miata SE - 6spd manual (wife's toy)

"Victory is mine!" - SG

Norman, OK

There is a little drippage, I always have the new switch ready to screw back into the hole so only a little is lost. Obviously I check the levels in both the trans and diff before I send the car out the door but I don't drain all the gear lube to do the job. If you remove the old switch and then take a nap on the creeper then the answer is YEP, lots of gear lube will be on your sleeve.

Steve

Thanks for the advice. I am planning to change the fluid so I will go the suction route. I just thought I was going crazy since the shop manual supplement for 64 shows the drain plugs. At least know I am somewhat sane. Thanks Again!

Keith
64 Monza Convert 110 4-speed
69 911T (IROC Clone)
"Horizontally Opposed"
05 GTO 6-speed (Gotta have a V8)
Chicago Burbs; the Anti-Dragon... 11 turns in 318 miles

Unfortunately the pics in the shop manuals aren't necessarily those of a particular year when they talk in generalizations. This is why lots of literature is handy, things like Bob Helts' books and the tech guide from CORSA.

Since you plan on changing the gear lube anyway the loss of lube from the backup light switch won't matter to you. One small caution, make sure the fiber washer under the old backup light switch doesn't get stuck in the hole, it will screw up the depth of the new switch and it won't work. I see many of the washers hang up in the trans case. Good luck.

Best, Steve