4 Speed Owners - Check Your Trans Tag

[68gt390]

How many of us who have a 4 speed actually have a "Close Ratio" tranny?
I'd almost bet every one of us with a 4 speed shows a code "5" on your Marti Report. Never really thought much about it until I put in the 428 and changed the input shaft on my 4 speed. I put in a new Hurst Shifter this weekend and started thinking about it again. With the old factory shifter now gone I can actually feel the difference in how the new Hurst Shifter and tranny work together (WOW). When I checked the tranny tag low and behold it is a "Close Ratio" 4 speed which is actually a code "6" but, my Marti Report shows my tranny as a 4 speed manual code "5". From all information I've been able to find the close ratio transmissions were a special order option except on the 428 CJ's, GT500's and the KR's. Again this just show's not all information documented at each factory is correct. My transmission also has the VIN stamped on it so it is original to the car.

Anyone else out there have more info or insight on this particular subject?

Don

 

[robert campbell]

Don,
I am going to do some digging. Certainly the VIN on your tranny is proof that it is the one that came with your car. What numbers on the tag denote a close ration (CR) from a wide ratio (WR) from your experience? My brother in law has a Ford Muscle Parts Identifier and Reference book. From his book an 1968 “R” code 428 4 speed car should have either a RUG-AE or and RUG-S tag number. The AE is a close ratio and the S is also a close ratio. The WR was not available in 68 behind the 428. This supports that the Marti report is incorrect. Do you have the original door tag or did you get it from Marti?? All and all you are absolutely correct!!! Your car can only be and should only be a code 6 on the door tag.

From my experience either a WR or CR can come with any Mustang throughout the years with yours seeming to be the exception. The 1 and 1/16 diameter input and the 1 and 3/8 diameter input both could be CR and WR. A lot big block cars came with the CR. The CR has a 2.32 ratio first gear and the WR has a 2.78 first gear ration. Most small blocks had a very tough time with the 2.32 ratio especially with tall gears (3.00's and 2.79) in thew rear end. Alot of clutch sliding to get them moving. BB cars had alot more torque and could get the car moving.

Lower rear end gears were prominent in the "high performance" options. 3.91 and 4.30 gears for the 69 and 70 drag pack cars. Certainly 3.50 and 3.25 gears in the alot of the 4 speed cars of 67 and 68. The Boss 302 with 4.30 gears could be ordered with a CR or WR to my experience. With 4.30 gears the first gear ration becomes pretty moot? With big engines and low gears getting that 2.32 ratio moving is no problem!!! Why am I telling you, you have a 428 car!!! The only problem with that car going forward is traction!!!

Also of note is the "front bearing snout" of a big block tranny. The snout that goes into the crank bearing that supports the engine end of the input shaft that goes into the clutch. A big block input shaft is very short (about 3/4 of an inch and the small block input shaft is around 1 and 1/2 inch. You can swap the input shaft out to allow a big block tranny to go behind a small block. Or you can purchase a "thicker" crank bushing for a small block that will reach the shorter snout of big block input install in a small block car. Whew!!! Did that make sense??

I rebuild top loader Ford speeds for people and perform these swaps. I have all the info on bearings small parts kits, and the unique high wear items for toploaders such as the syncro detent energizing springs that are the death of many a top loader. I also will build you a “crash box” if you want some real quick shifting!!

The most definitive way to tell between a CR and a WR is the “cluster” gear. From my experience all cluster gears from the WR cars have a “ring” cast into the gear between the front (input drive gear) and center gears and the rear gear and the center gears. You have to have the tranny out and the top off.

All in all I am curious if you have the original door tag or did you get it from Marti??. I have a discrepancy in another thread about a possible incorrect dealer code number on my Marti report for my GT/CS.

Rob

 

[68gt390]

Rob;
I should have mentioned that my car is originally an "S" code 390 car. Your tag codes for the true 428 CJ's are correct. The tag on my tranny reads RUG-AD which would be correct for the optional close ratio 4 speed in the GT 390 although my marti report and door tag both read code "5" for my tranny. That's why I found it odd I had the close ratio identifier when we dropped the tranny to do the work. This code was also used for the GT 500 but, not the KR cars. We swaped out the input shaft in my trans for the bigger 428 input shaft when we put the motor in last year. Sorry for the confusion.

Don

 

[robert campbell]

Don,
The books I have confirm your findings! Not that you needed confirmation. This is another example in that human beings and not robots assembled these cars. That discrepancies occurred on the line that contradicts what is in the Ford Database as how it was ordered. I bet your car is a case of an honest mistake or the lack of a WR in the “tranny bin” when it came down the line. Rule 1 is the assembly line does not stop!

Wow what a cool car! Nothing like the torque of a big block!!

Rob

 

[68gt390]

Wow what a cool car! Nothing like the torque of a big block!!

Rob

Thanks Rob. She's definitely a torque monster and blast to drive. She had power and torque even with the 390 but, you can definitely feel the difference with the 428 CJ. And now that the tranny works like it should it's even more fun to play with.

Don :grin:

 

[somethingspecial]

Don, My car too has the RUG-AD trans, S/N to the car, and behind a GT390. The Marti and the Door tag has a #5 for a trans. Build date of 04-5-68. Mike

 

[68gt390]

Mike;
I'd almost bet everyone of us with a big block (390 GT) 4 speed has the special order close ratio trans. Kinda wonder if Ford really even reported the differences in the two transmissions? Either way, I'm glad to have the close ration set-up. It's also good info to have when selling the car. Big difference between having the wide-ratio and close-ratio tranny.


Don

 

[robert campbell]

Don,
I agree. My brother-in-laws 67 GT 390 4 speed car has a CR also(VIN stamped in the case). My experince with big block cars is they mostly got the CR tranny. In 67 there was no difference in the door tag. One number (5) fit both. I wonder if early 68 cars may not have got the 6 code with a 4 speed CR?? Or if it was a mistake on the stamping. Another fun anamoly to run to the ground!!! Is your car a fairly early one of the 68 run?

Rob

 

[68gt390]

Rob;
She was built 16 Apr 68. She was about mid pack as far as build dates go. I could be wrong but, from what I've seen so far there were a lot of big block 390 cars with 4 speeds that went to the Seattle WA area (DSO 74) and farther north. Just something else to give us more to talk about. Heck, who knows - Ford may have decided to just continue using the "5" stamp for both transmissions although my book shows that 67 just had the "5" for 4 speed and didn't show CR or WR were as they added the "6", CR for 68 year cars. Maybe another way to save money and not have to change the stamping process.

Don :grin:

 

[robert campbell]

Don,
More proof that the human element was in full force, or just a slow shift to what we are told that happened!! It would be so cool to jump in the "way back" machine and find out what really happened! Aw heck, it gives us something to think about before our brains turn to mush...

Rob