2.7 Adv 4x4 OBX 2 Door Build - Front LSD, HF Winch, RC Hidden Mount/Skid Plate - DUNDRTY

[da_jokker]

It definitely will work, but not until I move the heat exchanger.

Lol..you first But I think I remember catching that your Bronco is on dirt mountain and you're in the military... So hopefully you'll get it soon and can answer the question for All of us, especially since RC isn't.

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[NC_Pinz]

I decided not to Sasquatch because I didn't want to run 35's or run 4.70 gears, so I compromised by getting a rear locker and 4.27 gears with those ugly ass 18 inch OBX rims.

The helical geared LSD's are usually pretty good for handling around corners without being overly aggressive (which is why you find them in Miatas). The upside is that it shouldn't be a problem with the handling anymore than it is in the F-150 Raptor (which is running a similar setup - rear locker, front helical lsd).

There are upsides and downsides of the these Torsen style differentials. Most notable downside is that if you lift a wheel, the other wheel will not get any power... Both wheels must have some traction.

For instance, in a 4:1 bias Torsen, if the loose wheel can only manage 10 ft/lbs of engine torque before slipping, then the maximum amount of torque that can be applied to the other wheel would be 40 ft/lbs. This makes them great for Baja type runs, but absolute shit for rock-crawling.

Fair enough I was curious. My '75 has an OE clutch style LSD and the handling on road is not fun. Your build will be fun to watch.

 

[mpeugeot]

Lol..you first But I think I remember catching that your Bronco is on dirt mountain and you're in the military... So hopefully you'll get it soon and can answer the question for All of us, especially since RC isn't.

That is correct on both counts.

 

[mpeugeot]

So this is the functionality that I am going for.




I also considered a Spartan locker, but I think that is possibly the wrong choice long term, but it would be a less expensive option.

 

[mpeugeot]

So here's the plan with the gears...

I will run either the 4.27 front gear, which I believe won't fit based on the information I got, or I am going to re-gear both axles to 5.13:1 gears. I considered 4.10:1 gears, but 70 MPH in 10th at 1,887 RPM and idling at 809 RPM at 30 MPH seems silly.

So what would that mean in a practical sense, well, I am assuming that fuel economy could decrease somewhat (although, at cruising speed, if the engine is near its torque peak that doesn't really make sense as the volumetric efficiency would be expected to be pretty high and this vehicle has a stupid amount of over-drive).

10th gear with 1:1 selected in the transfer case:

Speed	32" Tire Stock OBX	33.5" Tire w/5.13's
30	882 RPM	1,012 RPM
70	2,058 RPM	2,362 RPM
85	2,499 RPM	2,868 RPM

1st gear with 3.06:1 selected in the transfer case:

RPM	32" Tire Stock OBX	33.5" Tire w/5.13's
1000	1.5 MPH	1.3 MPH
3000	4.5 MPH	3.9 MPH
5000	7.5 MPH	6.5 MPH

Crawl ratio goes from 61.6:1 to 74.0:1, which won't hurt and still be able to hit 60 MPH in 4L.

Anyway, the TrueTrac arrived yesterday and the 5.13's are on the way.... Still need my Bronco. LOL.

 

[mpeugeot]

Don't be me and keep ordering the wrong stuff... LOL. I am closing in on what is right, but this is one of those things (Dana axles - I have done lots of other JDM stuff but this is out of my wheelhouse for sure!) that I know nothing about and I am going to painfully educate myself on.

BTW looking at some Ford documents, they use Dana 44 and M220 interchangeably, so it might likely be that. The M190 gears are definitely the reverse cut gears. Looking for M190 stuff I saw that M-4209-470RF was a 4.70 gear for the M190. Also M-4209-513 was a Dana 44 5.13 gear and M-4209-513BF was the matching front gear for the M210.

 

[mpeugeot]

So, here is an interesting observation, Ford is planning to offer a 4.70 ring and pinion for the M190 (M-4209-470RF). That would suggest to me that the ring gear would need not to be welded if they are planning to sell them separately from the differential housing... That would be awesome news, as it means that I might only need swap carriers initially.

The plot thickens.

 

[mpeugeot]

Well part of this project also includes a slight tweak to the suspension. I didn't want to get a Badlands interior (otherwise, I would probably had just ordered a badlands) and I did really want an Outer Banks either... I sort had wanted a WildTrak, but also not quite full Sasquatch. No one trim really did it for me.

Well, that left me with a bit of a dilemma. How to get everything that I wanted.

I did a little research and found the following:

2D 2.7 OBX No Sasquatch
Shocks F: MB3Z-1824-A R: MB3Z-1825-A
Springs F: MB3Z-5310-M R: MB3Z-5560-D
Bump Stops F: MB3Z-18198-B R: MB3Z-5K570-B

2D 2.7 Badlands No Sasquatch
Shocks F: MB3Z-1824-D R: MB3Z-1825-D
Springs F: MB3Z-5310-K R: MB3Z-5560-F
Bump Stops F: MB3Z-18198-C R: MB3Z-5K570-C

2D 2.7 OBX Sasquatch
Shocks F: MB3Z-1824-J R: MB3Z-1825-K
Springs F: MB3Z-5310-F R: MB3Z-5560-F
Bump Stops F: MB3Z-18198-C R: MB3Z-5K570-C

So rather than do a 1" spacer lift (which would be cheap), I am going to upgrade to the Badlands No Sasquatch Suspension

Parts list for the change:
Front -
MB3Z-1824-D (x2) Front Shocks
MB3Z-5310-K (x2) Front Springs
MB3Z-18198-C (x2) Front Stops
Rear -
MB3Z-1825-D (x2) Rear Shocks
MB3Z-5560-F (x2) Rear Springs
MB3Z-5K570-C (x2) Rear Stops

Hope to get a Bronco to install these on... Special thanks to @flip for helping me research this!!!

 

[mpeugeot]

Well, I wish I could report some kind of progress, but other than the shocks, springs, and stops having been shipped, not much to report as far as the actual build.

One of the other things that I did want to do was to put a thermal camera into the Bronco somewhere outside the cabin (where the image sensor and lens would be able to actually see). Thermal unlike night vision cannot hide behind glass and even low magnification high quality thermal sensors (640x480) are not cheap, so the idea of taking damage to the lens had me worried. The one thing that I did find was some plastic films that appeared to have minimal impact to the ability to continue to get good thermal images. Naturally, even a thin plastic film would provide a measure of safety for the lens. Acrylic, BTW, is not transparent to thermal sensors.

 

[jonesh242]

As it looks right now, I will probably be running 4.56's. The Dana 30 4.27 gears may not work with the setup I have (and no other 4.27 gears are currently available from the aftermarket). 4.56 front and rear gears are available however. The Torsen diffential should arrive today.



Unfortunately, not yet. I have most of the other parts in hand.



It's not clickbait, I have the winch and Rough Country mount right next to me. It is my already built Bronco that's missing!

The concensus is correct, until I relocate the heat exchanger. It's not really a cooler, because all it does is keep the transmission fluid at the same temperature as the radiator.

So the question becomes, do I relocate it or replace it with a cooler. Obviously, I will have to make a choice. The one thing that I am sure of is that it won't work as is.

I'm VERY interested in how you accomplish this...as in, I really hope it works out steller for you. I (hopefully) have a 2.7L BL w/capable bumper coming in the next 3-6 months (fingers crossed) and LOVE this RC kit set up. I'm not overly impressed by some of the aftermarket bumpers that stick SO FAR out in the front. I want a better approach angle. Post some pics if/when you get around to it. Cheers.

 

[mpeugeot]

I'm VERY interested in how you accomplish this...as in, I really hope it works out steller for you. I (hopefully) have a 2.7L BL w/capable bumper coming in the next 3-6 months (fingers crossed) and LOVE this RC kit set up. I'm not overly impressed by some of the aftermarket bumpers that stick SO FAR out in the front. I want a better approach angle. Post some pics if/when you get around to it. Cheers.

Well I have a Bronco now. I would expect the winch to be one of the last things that I address, because, I want to get the engine break-in/blow-up done first. However, I will eventually get it all done over the next few weeks. I have a whole bunch of little stuff to get out of the way first.

 

[da_jokker]

Well I have a Bronco now. I would expect the winch to be one of the last things that I address, because, I want to get the engine break-in/blow-up done first. However, I will eventually get it all done over the next few weeks. I have a whole bunch of little stuff to get out of the way first.

Yeah I totally get wanting to make sure that your engine is not one of the affected 2.7's especially since it seems like it falls inside that batch. But I'm on the edge of my seat waiting for you to figure out if you can relocate that heat exchanger...so hurry your ass up

 

[ohvrider]

If you wheelin alot should get front locker too. I got tired of banging on my sway bar with a rubber mallet on my 3 jeeps so sway bar disconnect is #1 reason I going after a bronco instead of a diesel AEV Jeep that I planned. Other is I don't need a truck to get it to Moab. I can just drive it. I think 35's are ok on 2-door but 4-door's will probably have to go 37's just like the 4door jeeps. With 35's they high center alot still.

Winch only works for recovery when there is something to attach too. In sand or open areas they can't be used. If you always have a buddy then you good., #1 recovery tool is probably a shovel.

I plan to save some money to upgrade weak spots, so far tie rods seem like #1 issue as several people have busted them. New jeeps had issue with steering box, all cars have weak spots.

 

[mpeugeot]

If you wheelin alot should get front locker too. I got tired of banging on my sway bar with a rubber mallet on my 3 jeeps so sway bar disconnect is #1 reason I going after a bronco instead of a diesel AEV Jeep that I planned. Other is I don't need a truck to get it to Moab. I can just drive it. I think 35's are ok on 2-door but 4-door's will probably have to go 37's just like the 4door jeeps. With 35's they high center alot still.

Winch only works for recovery when there is something to attach too. In sand or open areas they can't be used. If you always have a buddy then you good., #1 recovery tool is probably a shovel.

I plan to save some money to upgrade weak spots, so far tie rods seem like #1 issue as several people have busted them. New jeeps had issue with steering box, all cars have weak spots.

I tend to prefer high speed Baja type off-roading. I would be much more likely to be in sand or snow where a TrueTrac would shine.

It's not true that a winch cannot be used in open areas or sand. There are options for winching in areas that have little to attach the winch to, they are called ground anchors.

I agree, there are going to be things like tie rods which will need upgrading. Since I am not really "wheelin", I am pretty sure that the 33.5" tires are going to be overkill for most everything I am going to do.

 

[ohvrider]

I tend to prefer high speed Baja type off-roading. I would be much more likely to be in sand or snow where a TrueTrac would shine.

It's not true that a winch cannot be used in open areas or sand. There are options for winching in areas that have little to attach the winch to, they are called ground anchors.

I agree, there are going to be things like tie rods which will need upgrading. Since I am not really "wheelin", I am pretty sure that the 33.5" tires are going to be overkill for most everything I am going to do.

The performance of my Raptor on some old logging roads where others got stuck really sold me on the bronco. I wanted something with similar capability but much smaller.

One of the things I hated in my 2 door Jeep was that it like to bounce a little when starting have issues with traction. I see lots of other Jeeps doing same. I was told by some it was due to short wheel base, and others it was due to light weight. Either way i expect the bronco to do better in that area as well.

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