47 pickup tranny
 

I have a 47 pickup with an 8BA and want to get it on the highway. the standard 3 speed is slow. what is the best standard tranny to connect to the 8BA. I appreciate your help. God Bless

Re: 47 pickup tranny
 

If by "slow", you mean that the top speed is limited and it is unsuitable for highway use, the problem is the rear-end ratio not the transmission. All contemporary Ford transmissions that would fit your vehicle have a top gear ratio of 1:1, meaning they would all have the same top speed. You need to change out the rear end for one with a higher (lower numerically lower) rear end. For example, change from a 4:11 to a 3:54. You can change the gear set in the original rear end or get a complete assembly with a more suitable ration out of another similar vehicle. Or you could do some modification to the vehicle to replace the existing rear end with one out of a later model vehicle with a more suitable ratio.

You also could change the transmission for one from a later vehicle with an overdrive top gear, such as a Borg-Warner T5. Many have done this, but it a relatively complicated swap requiring aftermarket parts and some custom fabrication. Since your pickup has an open rear drive instead of a torque-tube (like the cars) changing the rear end is a little less difficult.

It takes a little research and planning to come up with a satisfactory combination. Once you decide which way you want to go, there is a lot of information available (here and other places) that will be helpful in your obtaining the desired outcome.

Re: 47 pickup tranny
 

The 1949-50 Mercury overdrive transmission would be a pretty easy swap into the 46-47 pickup truck but you would have to find a column shifter to work with it since it’s a side loader type that is made for the steering column shifter. Back in the day, Hurst made a floor shift conversion kit for the Merc overdrive but it would be a tough item to find now. Perhaps one of the available kits made these days could be adapted.

Re: 47 pickup tranny
 

Mac's got it.........the Merc OD drops a 4:11 to about 3:00. No aftermkt shifters for
this specifically anymore but I've done two conversions using the Spark o Matic shifters
(swap meet stuff) and a bit of adaptation...no big deal. Lots of these Merc OD trans are out there.
Charlie ny

Re: 47 pickup tranny
 

I'd assume the original truck rear end has 4:11 or lower gear ratio, no?

Would it be easier to swap the rear gears vs. adapting a different trans?

Re: 47 pickup tranny
 

I would give these folks a call about a replacement ring/gear set: https://www.randysworldwide.com/

Re: 47 pickup tranny
 

By slow I mean 45 mph top speed in 3rd gear. I have a 9" with 3.55 in the rear. Ill look around for a 49-50 Merc OD.

Re: 47 pickup tranny
 

if your 3 speed is open drive I would put a later rear like an 8in ford with 3:50 3:25 gearing,i had a 46 pu w/4speed open drive,replaced rear with an 70s torino rear and ran 65 mph, just had to mount new spring perches easy peasy,if you can locate a 68-72 bronco rear it will have the same wheel bolt pattern.

Re: 47 pickup tranny
 

With 3.55 gears in the rear end you should be capable of well over 45 mph in 3rd. What kind of rpm are you turning at that speed?

Re: 47 pickup tranny
 

Agreed. Regardless of your transmission, 3rd gear is a 1:1 ratio. 3:55's are a nice gear set. Something else seems to be amiss.

My dad has a '49 F1 with heavy duty 3 speed and 4:11's and it will do 65 all day long.

Re: 47 pickup tranny
 

I have a 3 speed in my 41 and 3.54 ears, with 6.50:16s. It runs nice at 45 and will go quicker if I want.

If your truck tops out at 45 there is something not right. It should go a lot quicker than that as standard.

I'd suggest you look at the motor first, it must be very short on power or there is something stopping it from revving through the range.

Mart.

Re: 47 pickup tranny
 

51 merc engine, 77 b cam, 3 speed 28 tooth cluster (car) 9" with 3.25 gear set, runs easy at 60 mph, I have had it a lot faster! I would change out the 3:55 for a 3:25 easy change for a 9" just how hilly is your area?

Re: 47 pickup tranny
 

What are you running for a tire? My 49 F! with a stock 239 +.100 will run all day 70 mph 3.25 9" rear. 275/60/15 rubber 28" You may even want to consider a S10 5 speed.

Re: 47 pickup tranny
 

A60hp with 4:44 rear I had would do 74mph, either your brakes are dragging or the engine is low on power

Re: 47 pickup tranny
 

Agreed. Something is wrong.

Re: 47 pickup tranny
 

I think the OP has twigged what we have been saying, he has posted another thread saying his 8BA is down on power.

https://www.fordbarn.com/forum/showthread.php?t=275006

Mart.

Re: 47 pickup tranny
 

If you don't have the power to pull a 3.55 rear gear over 45 MPH, an overdrive will be totally useless to you. You need to find out what is wrong with the engine. Ray

Re: 47 pickup tranny
 

If everything is right with the engine,compression,timing,fuel pump and you are getting full throttle make sure mice aren't squatting in your exhaust system. Even with a 3.55 gear the truck should run 65 mph @3,000 rpm with a 26.5 tall tire thereabouts.

Re: 47 pickup tranny
 

thanks for the replies. something is a miss. I have another thread trying to figure out a power issue and maybe they are the same issue. the tires are 255/60R15's. I dont have a tach but will mount one this weekend so I can see. it revs up real nice in idle but just bogs down on the road. I do have a hesitation when I punch it, it almost dies like its getting too much gas. has a big sucking noise. if I east into it, it accelerates well.

the exhaust is new so all is clean, or should be. I will check.

ill check compression too. havent done that yet.

ill post photos when I remember how again. ...God Bless

Re: 47 pickup tranny
 

I'd almost bet you have an issue with the carb. It could have an issue internally especially if it isn't driven much and has ethanol fuel in it. I would put another carb. on there from a running engine that you are positive works and that will rule that out. It may even be float level. From what I understand is the throttle blades are open and there is a lack of fuel atomizing in the venturi.