Not A Build Thread (Oh How Things Change!)

[Okie69]

I've decided to start an overall thread to assist in tracking discussions and advice about my EB as well as keep a record of a whole host of newbie questions throughout.

The plan is to update the second part of the title if and when I have a new question and this thread has moved down in the history.

Once I actually get rolling on the build I may move over to the chat section with an actual build thread for those that might be interested.


I have 1969 Bronco with no engine. ( more info on that here https://classicbroncos.com/forums/showthread.php?t=300016 ) it has a 3.5" suspension lift that is old and tired and will probably get replaced during this refresh. It has the stock 3 speed manual and D20 transfer case. Small bearing rear with the 10 inch drums and a D30 upfront that is in pieces after a fight that it lost with the 35s I put on it. I have a HP D44 that has been narrowed on both sides and has discs already on it sitting in a corner waiting to be installed. (more info on that here https://classicbroncos.com/forums/showthread.php?t=299705 )

For now I'm in the planning and dissasembly phase. I do not plan on taking the body off of the frame or doing any rust repair at this time. I will be taking steps to try and slow rust, but the body will have to wait for its day. The main purpose of this is to get my EB to a place where I can jump in it and drive anytime I want to without fear of it not starting or stopping or something in between.

The end goal for me is to be able to sell my truck and replace it with the Bronco. I have a company vehicle so it won't be used for commuting. My truck gets used a few times a month for go to places around town and every once and awhile I have to drive the few hours to my parents. I am sure I'll make more excuses to drive the Bronco once it is up and running, but that is the situation for now.

I envision a completely mechanically sound drivetrain that can handle this motor https://blueprintengines.com/produc...-dressed-longblock-fuel-injection-bp306maxctf with me being slightly heavy footed. I would like the combination of transmission and gearing to favor city driving and off road (torquey feeling) but also be able to able to cruise at 60-70mph on the rare occasion. The highway feel is definitely second to the in town and off road performance to me. The goal is a 70-30 street to trail kinda rig. I also need to keep everything as cheap as possible while still fitting the above criteria. I'll spend money if I need to, but that extends the timelines.

The timeline for ordering the motor is sometime in the end of '20 so everything I do is in preparation for that happening.

So onto the questions:

Everything working as a system as it does, I need suggestions for transmission and gearing for the above described driving style.

After some great information given in another thread I'm leaning towards either leaving my small bearing 28 spline rear alone for now and moving on to the other components. If and when it grenades I would move to a large bearing 31 spline setup. Or I could build up my small bearing housing with a 31 spline conversion and a stronger aftermarket 3rd member.

Transfer case? this is one of the areas I haven't researched very well yet I assume it will need some strengthening. I hope that it will not become a weak link. Suggestions?

I think I am going to stay away from traction devices for now so I can actually get back on the road then at a later date I'll tackle that part.

I think that's most everything for now. I look forward to reading what you guys think about the situation.

 

[jamesroney]

Maybe you should just buy this???

It would solve your small bearing housing problem. (and you could sell your small bearing axle and get almost all of your money back...)

Gets you 4.10's, trac lock, big bearings and big brakes.


https://www.classicbroncos.com/forums/showthread.php?t=298562

If you are near a Forward Air location, shipping would be reasonable.

(yeah, it's mine...)

 

[unimogger]

cheap as possible? NP435.
Need more gears? ZF5, and run a 205 transfer case to keep it cheap, as it will bolt right up.

 

[Okie69]

Maybe you should just buy this???



It would solve your small bearing housing problem. (and you could sell your small bearing axle and get almost all of your money back...)



Gets you 4.10's, trac lock, big bearings and big brakes.





https://www.classicbroncos.com/forums/showthread.php?t=298562



If you are near a Forward Air location, shipping would be reasonable.



(yeah, it's mine...)

Possibly once I get this all lined out!

 

[Okie69]

cheap as possible? NP435.

Need more gears? ZF5, and run a 205 transfer case to keep it cheap, as it will bolt right up.

I really don’t know if I need more gears. I don’t think so though. I am slightly worried about the NP435 “shifting like a truck” though.

 

[Okie69]

Got the old rear end out and cleaned up a little. I guess I’ll go ahead and clean and paint just in case.

Sent from my iPhone using Tapatalk

 

[.94 OR]

I measured my drive line angle before I had my rear axle out. I had to have a 6° shim to get things lined up. When I installed the longer perches I added the 6° to that measurement so I could lose the shims. Bonus, I could move the axle back 1" to center the tire in the opening... (feeding your snowball) ;D

 

[Okie69]

(feeding your snowball) ;D

Hey now. My snowball doesn’t need any help!


Sent from my iPhone using Tapatalk

 

[Okie69]

The more I look into it the more I think I would like to keep my 3 speed on the column for now. Thoughts on how long it will last with the added power? Or should I just swap over to the NP435 while I’ve got everything apart.

The shifter location and the tales of having to reach across the bronco to shift have me thinking twice.

 

[.94 OR]

If you don't need more gears and you are upgrading the rear end gears to handle the larger tires, the 3 speed may be perfectly fine. I don't think it will be your weakest link with more power. Tom's and likely other vendors have rebuild kits for the 3 speed for roughly $120. If it were me and I planned to retain that gearbox I would freshen it up and tighten up anything in the column shifter and call it good.

I went from the 3 speed in mine to the NP435 since I had one and wanted the granny gear. It shifts slower but I can reach all gears comfortably. This is not really the best cruising around town gearbox though so you may enjoy the quicker shifting 3 speed for your application.

 

[Okie69]

If you don't need more gears and you are upgrading the rear end gears to handle the larger tires, the 3 speed may be perfectly fine. I don't think it will be your weakest link with more power. Tom's and likely other vendors have rebuild kits for the 3 speed for roughly $120. If it were me and I planned to retain that gearbox I would freshen it up and tighten up anything in the column shifter and call it good.

That’s what I’m hoping too. I’ve already got the stuff to do the column shift rebuild. That was the plan before the snowball started rolling.

Next link in the chain. Will the D20 be able to hold up?

 

[73azbronco]

You already have it apart which is different than my usual advice, leave it alone.

That said, if you throw a blueprint motor and get on it, 3 on the tree and stock small dana will let lose. That, and no brakes to stop bigger motor safely. I'd do it while its all out.

Caution, it's taken me 6 years to get from where you are to getting ready to throw top on next week.

 

[Okie69]

You already have it apart which is different than my usual advice, leave it alone.

Leave it alone meaning? I've got the engine and rear end out. The transmission and transfer case are still in, but probably need a rebuild anyway.

That said, if you throw a blueprint motor and get on it, 3 on the tree and stock small dana will let lose. That, and no brakes to stop bigger motor safely. I'd do it while its all out.

I think I will just have to be disciplined enough to not drive it in a way that will break it. I've got discs going on the front and will probably be adding a power brake unit, but that discussion is for a later time.

Caution, it's taken me 6 years to get from where you are to getting ready to throw top on next week.

Congrats on getting to that point! You must be beyond excited!

I plan on having a motor at the end of the year, but I'm also getting a feeling I won't get to enjoy it for quite some time after.

 

[DirtDonk]

There's an upside to the proper gearing you'll be using in the differential that you can use to your advantage.
The lower your gearing (higher number) everything in front of that gearing has a better chance of survival.

With the wrong gearing (in this case 3.50's and 35" tires), literally everything between the engine producing the torque, and the tires resisting movement suffers. The new engine will task things for sure, but since you will also have changed the ring-n-pinion ratios prior to driving, you'll be in a better place (and can take it to the bank!).
Driving with the wrong gearing definitely makes it easier to find all the weak links, in order of strength.

With the 4.56 and 35's however, everything between the engine and differential is under less stress when getting 4,000 lbs of Bronco up and rolling. Leaves just the axle shafts holding the bag.
With the right gearing then, your trans and t-case won't feel so abused and might just last longer than you think. At that point it depends on your driving.

You can still break just about anything if you try hard enough of course. And now your axle shafts will definitely be the weaker links (although still pretty good for lightweight stock stuff, as far as that goes), but those are part of the end plan anyway, so I say you're good for the most part.

Paul

 

[DirtDonk]

Nice choice in front bumpers too! What's on the back? Stock type, or something else?
I helped design the over-rider and gave it it's name (Winch-Guard) too by the way!;D
Originally I wanted it to be just a little more like the old Cactus Smashers, but when we tried different shapes, these angles just looked right on the bumper.

Paul

 

[Okie69]

With the wrong gearing (in this case 3.50's and 35" tires), literally everything between the engine producing the torque, and the tires resisting movement suffers.

Really? I must’ve been thinking about it backwards. My initial thought was a lower gear 4.56 in this case would cause more stress due to the increased torque loads and having to spin the 35s further on each engine rotation.

I was even thinking of going with a slightly higher gear to ease some of the stress.

 

[Okie69]

Nice choice in front bumpers too! What's on the back? Stock type, or something else?
Paul

It’s a Hanson on the front. Is that what you thought or are the pictures deceiving?? Stock type on the rear for now but I’m going with the Hanson rear eventually.

 

[Nothing Special]

Really? I must’ve been thinking about it backwards. My initial thought was a lower gear 4.56 in this case would cause more stress due to the increased torque loads and having to spin the 35s further on each engine rotation.

I was even thinking of going with a slightly higher gear to ease some of the stress.

4.56 gears spin the tires LESS with each engine rotation. Or more directly, the engine spins more (4.56 times vs 3.5 times) for each tire rotation.


Think of it like a wrench handle. The longer it is the less hard you have to push on it but the farther your hand has to move to move the bolt the same amount. Low gears are like that. Everything in front of the gears has to move farther, but it doesn't have to push as hard to get the same thing done.

But like the long handle on the wrench, it means that you can put more load on everything down stream. That means that, like Paul said, the axles will take the brunt of it.

By the way, the same thing goes with trans and transfer case gearing. Getting happy with the new motor in 1st gear is harder on things than in 3rd. Getting happy with an NP435 in granny low is worse yet. And getting happy in low range can make you very sad!

Again, keep in mind that anything downstream of the low gears is at risk. The axle shafts always are. The transfer case will stress your driveshaft and diff. And the trans will stress the transfer case.

 

[Okie69]

That makes perfect sense. I was definitely thinking of it backwards. Thanks for the clarification!

That actually makes me feel a little optimistic. Maybe the 4.56 gears will keep me in the 3 speed and D20 for longer.

 

[Okie69]

Alright guys it's time to pull the trigger on some parts.

My goal is to get my small bearing 9" as strong as possible without replacing axles. My reasoning is I want to get this thing back together and will be going with a traction device in the future so trying to keep costs down at this time.

Thanks to Paul and .94 OR for the input and suggestions on my previous thread.

The first option is this ring and pinion
https://www.wildhorses4x4.com/product/Yukon-Ford-9in-Ring-Pinion-4-56-ratio/bronco_Rear_Differential

with this bearing kit.
https://www.quickperformance.com/Ford-9-Master-Bearing--Install-Kit-Timken-USA_p_13.html

I'm correct in picking the 2.89 carrier bearing size if I'm keeping the stock case right?

The next option. (If it is worth it in strength gain I would rather go with this)

Strange Nodular case
https://www.summitracing.com/parts/str-n2205/overview/

with the 3.06 version of the Timken kit.
https://www.quickperformance.com/Ford-9-Master-Bearing--Install-Kit-Timken-USA_p_13.html

and the same set of Yukon ring & pinion.

It looks like I need to do the conversion axles with this setup right? You can select a 28 spline axle for the case on the summit website but I don't see how that would work.

Long story short will these parts play nice together and give me added strength?