Tranny Swap

[party2849]

I own a 1984 Ford Bronco XLT with a 351W with a 4 speed manual. It has quite a bit of power with the current gears. However my RPMS are extremely high at high speeds and I get horrible gas mileage. What would I have to do in order to get and install a 5 spd with overdrive but still have good low end power?

 

[fordfanatic75]

obviously the first thing to do is aquire the trans and everthing with it. such as flexplate linkage and maybe even the flyweel. Different aps have diferent needs. keeping your low gears wouldn't be a problem, most transmision the final gear in your case 4th gear is 1-1, with the 5sp 4th would still be 1-1 and 5th would be somthing like 1 1/2 -1 thats your overdrive it would prably give you somthing like a 400 rpm drop.

 

[party2849]

Where is the best place to get the parts and about how much would it cost?

 

[fordfanatic75]

Where is the best place to get the parts and about how much would it cost?

19741[/snapback]

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It would realy depend on whether you wanted new or used. A great place to get bothwould jeffs bronco graveyard youcan look it up online. Just the way i spelled it only without the spaces. as far as cost you can tipicaly pick up a new one complete for somewhere between 1,200-2,000$. used from jeffs i'm not sure. if you could get lucky enough to find one in a boneyard maybe 200$ with everthing. not positiv but you maybe able to use one out of a mustang. by havingit built with the right tailshaft. thats what i did on my jeep!

 

[seawalkersee]

If you are not concerned about breakage. The five speed trannys in the p/u are crap. They are M5od and ****. They dont wear very well if you are ******* them. Trust someone whos dad only has manual trannys and fords. The last one lasted plenty well but it only had 60k on it and it was hard to shift from like 40k. The old man babied the thing and I think it was going out. His newest one is about 60k again and at times he cant git er into gear.

Just my .02.

Chris

 

[Justshootme84]

party2849, a good tranny to swap would be a ZF-S5-42. Both 2wd and 4wd versions of this 5-speed OD manual were offered in Ford trucks. Try doing a search to see what type of clutch you'll need, bellhousing fitment, etc. Bronco Driver magazine had a great tech article on adapting a 2wd version to fit a 4wd Bronco. A good place to look for the tranny and all of the parts would be a salvage yard. That way, you can get everything at one time, instead of buying the tranny and having to hunt down additional parts.

 

[seawalkersee]

The problem with the ZF is it is a big block tranny. The case is all one piece (non removable bell housing) but with machine work could be done. Or you could try to find an adapter plate.

Chris

 

[Justshootme84]

The Zf-5 sp. was offered on the 351W, a small block motor.

 

[seawalkersee]

Uhhhhhhh.....I will put this out here so you dont take offence. I do not slam in my posts but I will call someone out on ocasion. I worked for Ford for several years. I have buddies in shops still. In the Five tranny guys I worked with and my five years at Ford I NEVER SAW and was told Ford NEVER PUT a ZF in a small block pickup. If you are refering to the five speed tranny that came behind the f150 and f250s that would be a m5od. I however am not an expert AND we did not see a lot of the fleet services that would have been a f-250/350 with a 351. If I am wrong, show me proof. Once again I am not trying to insult you.

 

[Justshootme84]

I was going to post this anyway to show what 5-speeds are potentially available for the swap, but here's the proof:

Tranny guide

 

[party2849]

Justshootme : It seems like you are quite knowledgable of these vehicles, thank you so much for your advice. Would that zf 5 spd link up with the 84 bronco, just like your truck? and what will i have to change out with the tranny in order for it to be compatible

 

[seawalkersee]

I stand corrected and am sorry to have doubet you. I am however from the show me state so I can not take ALL of the blame. Kudos for the correction.

Chris

 

[Justshootme84]

Justshootme : It seems like you are quite knowledgable of these vehicles, thank you so much for your advice. Would that zf 5 spd link up with the 84 bronco, just like your truck? and what will i have to change out with the tranny in order for it to be compatible

19852[/snapback]

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THe 4-sp manual in your 84 Bronco could be a couple of different models, but most likely will have a bolt-on bellhousing. Like stated, the ZF- 5 sp has the bellhousing made into the tranny. THe clutch will likely not be the same, and the crossmember and driveshafts may need to be altered if the tranny size is not close to the same. But if a donor 5-sp manual, be it a Mazda or the ZF's, was originally mated to a smallblock like the 351W it is usually a direct bolt up to your motor. The hard part is finding one from a 4WD truck. ANd yes, I agree that the Mazda 5-sp is not a very strong tranny or really worth swapping.

I would start with searching through some salvage yards, and talk to those dudes. They will know what parts can be swapped in your truck. That's where I picked up a little info on the Ford trannies and transfer cases over the years.

 

[seawalkersee]

And If Im not mistaken you will have to get the ***** cyl from the new tranny as well. Your four speed has an externally mounted on. I know the M50D is internal but Im not sure about the ZF...JSM48?

Chris

 

[Straight6]

When swapping from one tranny to another, say an SROD to a ZF in an 83' Bronco, how will the new tranny line up with the access hole for the shifter in the floor of the truck. When answering this question please keep in mind that I have never swaped a transmission before but I fear that I may need to.

 

[seawalkersee]

The engines that the trannys bolt up to mount the exact same way. The tranny will sit in the exact same location. They came out of a truck that has the exact same set up body wise...does that help?

Chris

 

[Justshootme84]

There are two versions of the S5-42 ZF 5sp. A "light duty", which has a "concentric" or internal ***** cylinder. A "heavy duty" with an external ***** cylinder, but I'll bet that one is more common for the big block motor. And every manual tranny Bronco I've seen has the shifter hole in the same location on the floor ****.

 

[Straight6]

This is subject I'll need to come back to later on and I'll have many more questions but thanks for the responses it now seems like swapping out this SROD may not be such a big job after all.