When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi y'all, so I've been kind of restoring my recently acquired f-100 with a 3 on tree, 3 speed transmission mated to a 302 and I'm running into OEM Ford seals that have not been touched since assembly.
So, I'm going through random threads looking for Google searches about information related to my transmission. I've nailed down the transmission. It's a RAB which is not common on the David top loaders website but still has some of the same components. Ordered a seal kit from their website and have fortunately sourced some seals from my local auto parts, but I wanted to create this thread to create a consolidated information piece with links that I've discovered along this forum and on other websites like YouTube that has a complete rebuild.
For example, here's a youtube with a thorough break down of the 3 speed transmission
The transmission seemed to be running fine other than leaks and occasional crossing of the shift levers so I'm just trying to replace the seals and throw it back in and torque everything thing down hoping my shift rods were just loose.
To start off with, if any of you have any information about the rear seal I have questions.
Question 1 Which one is the proper one for my RAB transmission? I have the Ford e-manual and have the codes part numbers for them but given what what I pulled out has me confused.
2nd can anyone identify these seals and what transmission or application they went on?.
I know this transmission is popular on more than the truck so I am posting here. Hopefully some of y'all had relationships or experience with this transmission and the proper rear seal. They're giving these varying dimensions.
The seal in the right was for my "application" from the local auto parts. Came with the metal sleeve bushing too. the left is from a 3.03 transmission seal kit from davids top loader. Confirmation on which would work with the 74 because both of these dont match the after market one i pulled from the transmission housing. https://www.npdlink.com/product/oil-...housing/105624
the right seal is a tail shaft "extension"?
3rd
Can I replace the o-rings on the shift arms without pulling out the guts from the transmission?
I don't recall the part number of the rear main shaft seal, but if you can, get the type on the right, with the shoulder that provides a positive stop.
I had to disassemble the whole thing to replace those O-rings on the shift arms.
My assembly worked great, mostly; no leaks for the first several months that I used it, but it had occasional grinds going from first to second, no matter how carefully I clutched and shifted. I later found out that the GL5 lube I used was not recommended for old-style synchromesh transmissions, as their formulation have different friction characteristics and may also damage the brass blocker rings.
There are lubes made specifically for that type of transmission; I got the stuff from Valvoline. It definitely made shifting smoother; no more grinding. But after a few months, I found that it leaked out of just about everywhere on the transmission that it can, including those O-rings on the shift arms. I was told that it may be due to the Valvoline formulation.
If you're getting binding while shifting through that three-on-the-tree, check the bushings on shift linkages, and the shift tube the runs from the lever down to the bottom of the column. I had one a long time ago, and the bottom of the tube had basically a "tooth" that stuck out of the tube that engaged one of two shift arms at the base of the column. Each arm had a lever, each of which had linkages that went to the shift arms on the transmission. Each connection had a rubber or plastic bushing that wore out, and the slop occasionally caused binding. I had to fight them to unbind them, which put enough stress on that "tooth" to break it off of the bottom of the shift tube.
I don't recall the part number of the rear main shaft seal, but if you can, get the type on the right, with the shoulder that provides a positive stop.
I had to disassemble the whole thing to replace those O-rings on the shift arms.
My assembly worked great, mostly; no leaks for the first several months that I used it, but it had occasional grinds going from first to second, no matter how carefully I clutched and shifted. I later found out that the GL5 lube I used was not recommended for old-style synchromesh transmissions, as their formulation have different friction characteristics and may also damage the brass blocker rings.
There are lubes made specifically for that type of transmission; I got the stuff from Valvoline. It definitely made shifting smoother; no more grinding. But after a few months, I found that it leaked out of just about everywhere on the transmission that it can, including those O-rings on the shift arms. I was told that it may be due to the Valvoline formulation.
If you're getting binding while shifting through that three-on-the-tree, check the bushings on shift linkages, and the shift tube the runs from the lever down to the bottom of the column. I had one a long time ago, and the bottom of the tube had basically a "tooth" that stuck out of the tube that engaged one of two shift arms at the base of the column. Each arm had a lever, each of which had linkages that went to the shift arms on the transmission. Each connection had a rubber or plastic bushing that wore out, and the slop occasionally caused binding. I had to fight them to unbind them, which put enough stress on that "tooth" to break it off of the bottom of the shift tube.
I eventually folded and got a shop to rebuild it and throw new syncros. I feel kinda good because this guy had building transmissions for 45 yrs and was surprised to see mine because he hasnt seen one in a while. lll get pics soon of the new pieces and now that i have space under the truck i removed the shifting pieces to de-grime and paint up and im noticing some serious wear that im considering buying new pieces from LMC
