1967 Family Patrol Project

Builds, refurbishments, restorations, upgrades

Postby faux40 » Thu Oct 08, 2020 10:00 am

I did a little digging though the boxes that came with the Patrol way back when we got it... LOOKIE! A pair of inner bearings for the front axle! Factory Nissan Bearings no less! Note that the Nissan PN is 40211-45460 while the bearing is tamped NSK HR 30209J
7378
7379

John
faux40 Offline

User avatar
Administrator
Administrator
 
Posts: 1206
Images: 1310
Joined: Sun Jul 28, 2013 12:45 am
Has thanked: 635 times
Been thanked: 1116 times
Location: Roseville, California

Postby Esteban » Thu Oct 08, 2020 5:51 pm

faux40 wrote:I did a little digging though the boxes that came with the Patrol way back when we got it... LOOKIE! A pair of inner bearings for the front axle! Factory Nissan Bearings no less! Note that the Nissan PN is 40211-45460 while the bearing is tamped NSK HR 30209J

John


Pure p0rn!! :clap: :clap: :clap:
Owner of the same Patrol since 1967
Esteban Offline

User avatar
Patrol Fanatic!
Patrol Fanatic!
 
Posts: 2849
Joined: Sat Feb 23, 2013 11:28 am
Location: Lutherville, MD
Has thanked: 5548 times
Been thanked: 1432 times
Location: Lutherville, MD

Postby faux40 » Sun Oct 11, 2020 12:29 am

Today was rip-it-apart day!

Step 1 - Make a bearing bolt tool
7397

Step 2 - Test that the tool engages the nut (okay, so I spilled the beans and showed an after picture...)
7398

Step 3 - Fully engage the nut and get ready to twist!
7400

Step 4 - Grab a simple piece of scrap to use as a lever -- And BOOM!
7401

Results - The Bearing that was installed is an NSK 30208
7396

I bought the Harbor Freight Press -- it's on sale. Sadly, it won't work with this axle.. In fact I bent one of the ears on the bearing housing trying! Dang it! I'm working on a solution to make it work...

John
faux40 Offline

User avatar
Administrator
Administrator
 
Posts: 1206
Images: 1310
Joined: Sun Jul 28, 2013 12:45 am
Has thanked: 635 times
Been thanked: 1116 times
Location: Roseville, California

Postby RiverPatrol » Sun Oct 11, 2020 9:07 am

Excellent tool!
Beyond any hope for intervention

Image
RiverPatrol Offline

User avatar
Administrator
Administrator
 
Posts: 7423
Images: 959
Joined: Thu Oct 04, 2012 10:42 am
Has thanked: 6753 times
Been thanked: 2280 times
Location: Temecula, CA

Postby faux40 » Sun Oct 11, 2020 3:13 pm

So, here's the on-sale harbor freight press -- not bad quality. Although the cross bar is not wide enough (front to back) to allow the wheel mounting flange to slip through -- But, to quote Galaxy Quest -- Never give up, never surrender!
7408


I found a way using using stuff laying around to create a perch to push that bearing out. A chuck of 1/4" thick steel and an industrial storm drain grate that just showed up here years ago. A little plasma-action and voila!
7407

Boom! The bearing is out... But at pretty a high cost... crap! The hub slipped a tiny bit in the press and tweaked two mounting bolt holes. At least the bends are smack in the middle of the bolt holes, leaving the sealing surface in fine shape. Next, I'll take it to my friendly neighborhood machine shop and have them knock is back to shape and then re-face it.
7410

But, it does look good with the disk don't you think? I'm semi-mostly-committed to four-wheel disks
7409

Question: What centers the drums on the axle? Is it the center hole, or the wheel studs? Is that the same way disks are typically centered?

J
faux40 Offline

User avatar
Administrator
Administrator
 
Posts: 1206
Images: 1310
Joined: Sun Jul 28, 2013 12:45 am
Has thanked: 635 times
Been thanked: 1116 times
Location: Roseville, California

Postby faux40 » Mon Oct 19, 2020 11:54 pm

Big adventure! Popped over to Sacramento Spring and picked up Aerogirl's newly re-conditioned Patrol springs!
7421

Some of the cool spring making equipment
7420

And snacks! (assuming you find metal chunks delicious! -;) )
7419

So, here they are! I asked them to beef them up a little so make sure the patrol doesn't sag under load! They look really good, don't they?
7418

Okie, I was joking... Here they are on their way to the truck.
7417

Funny thing -- one leaf has been replaced at some point. Notice the second spring layer on each front spring. One is much, much thicker than the other.
7422

Aaannnd... Lookie what made it up to the work area! ;-)
7423

John
faux40 Offline

User avatar
Administrator
Administrator
 
Posts: 1206
Images: 1310
Joined: Sun Jul 28, 2013 12:45 am
Has thanked: 635 times
Been thanked: 1116 times
Location: Roseville, California

Postby faux40 » Wed Oct 21, 2020 1:34 am

Okie doke -- Time to start on the brakes! And, yes a very long winded post!

I'm planning on going disk in front and disk in back. I've considered the classic full-size GM 4x4 disk setup. But I keep going back to the GM thing... nothing against GM, but I'd like to stay Nissan as much as possible. So, I'm thinking later Frontier trucks... just like mine! Turns out that the 4,426 lbs. curb weight of the Frontier 4x4 crew cab is just about the same as the Patrol's 4,575 lbs gross weight -- Additionally, the Patrol tops out at 70mph (with some serious white knuckles) where as the Frontier, even at is 5,816 lbs gross weight, will still probably top out over 100 mph! With that in mind, I'm pretty sure the Frontier brakes will have plenty of stopping-power and thermal capacity. My plan is to change everything... except the actual brake pedal! Even so, I'm finding two big challenges in the conversion from drum/drum to disk/disk.

Nissan Frontier front caliper and rotor
7430

Design Challenge 1
The Patrol is short and tall. This means that in a maximum effort stop, the dynamic weight transfer is significant... meaning it is really easy to lock up the rear wheels!

Design Challenge 2
The Patrol's brake pedal is long and yields a 7:1-ish pedal ratio. According to the internet, vehicles with manual brakes generally use a 6:1 pedal ratio. I'm guessing since the Patrol is a truck, they went a little high on the ratio to keep the brake pressure manageable at a gross weight, overland expedition trek! Vehicles with power brakes often have a 4:1 or even a 3:1 pedal ratio. The problem with too long a ratio is that the brakes may turn out to be sensitive and touchy!
1710-157-GM-muscle-car-brake-pedal-two-pushrod-holes-CALLOUT.jpg


------------------------------------------------------------------------------------------------

So, to tackle the first challenge I need to calculate how much the dynamic weight transfer actually occurs at a maximum effort stop (think panic stop). First off, I did all the calcs in metric units... Sorry! So, it turns out that at minimum weight, the transfer is 455 kg from the back axle to the front axle. Since the weight on the rear axle only started with 740 kg, there's only 285 kg remaining on those back wheels... that's not a lot left pushing down on those tires. They'll be quite easy to lock up. At gross weight, the transfer is even more! At gross, the rear axle starts at 845 kg -- during that panic stop, 604 kg moves forward leaving 626 kg pushing those rear wheels down - which is good... except that the additional 510 kg of mass that we have to slow down really wants to keep going full speed!

That same dynamic weight transfer goes the opposite direction when talking about the front axle. The min front axle weight goes from 825 kg to 1,280 kg. At gross weight the transfer is even bigger -- from 845 kg on the front axle at gross weight to 1,449 kg on that axle during a max stop!

This means that those back tires are really easy to get skidding long before the fronts are out of grip! This can often be addressed using an adjustable rear brake proportioning valve... but there just may not be enough adjustment in the valve to compensate for the large difference in the front and rear braking needs. Another way to adjust the F/R balance is to make the rear brakes smaller. By choosing a matched set of brakes from a truck, the under sized rear disks are already part of the package!

------------------------------------------------------------------------------------------------

The second challenge is is that pedal ratio -- weird, right? Using the 295.6 mm rotor diameter (just under 12"), an average tire grip factor, the rolling tire radius, and the weight on that front axle means that the brakes must generate 2,395 Nm of torque (1,766 ft.lbs) to keep those front tires stopping at their best rate. Next, I had to figure out what kind of hydraulic pressure the caliper needs to generate that kind of torque -- Turns out to be 9,778 kPa of pressure is required! (A.K.A. 1,418 psi -- again, sorry about the metric units!)

During the same stop, the rear brakes only need 6,453 kPa (936 psi) to achieve the needed 1,014 Nm of torque (748 ft.lbs.) to contribute to the emergency stop without skidding. At min weight, the braking split is 75% front, 25% rear. At gross weight, it's a 60% front, 40% rear split.

To generate this kind of force, we have to back-through the system and figure out how hard our foot needs to press. The internet suggests that number should be in the 75 pound range. Using the master cylinder diameter of 25.4 mm (1") and the two-per caliper slave cylinders on the front (123 mm x 2 per caliper) and rear slave cylinder piston diameter (118 mm x 1 per caliper), and the pedal ratio, the pressure achieved is only 4,608 kPa (668 psi) -- no where enough pressure for a max stop. To get the 1,481 psi needed, we'd need to press on the pedal with over 150 pounds - And that is way, way too much effort to get to max stopping power! Note that the classic GM 4x4 front caliper has more piston area, so it will work at lower pressures but then it wouldn't have Nissan brakes!

But, if we add a small vacuum booster to the system, we can multiply our foot pressure a whole bunch. Vac boosters range from a factor of about 2:1 to 8:1... but none publish this number! I'm assuming I'll only need a small-ish one, so I used a 3:1 factor in my calcs. With that booster, 35 kg (77 lbs) of force on the pedal will yield a little over 2,000 psi in the system! So we'd have room to spare! Enough that I may tweak the pedal enough to lower it's ratio to 6:1 or so to keep the brakes from being too sensitive. At 6:1, that same 77 lbs push still yields a respectable 1,769 psi in the system... which still has some room to spare!

------------------------------------------------------------------------------------------------

So, in a nutshell, that is my plan and these are my calcs -- Honestly, I suspect that my calcs have errors. There were a ton of assumptions so I'll likely be refining my calcs before ever needing to stop the Patrol from rolling! Here's my calculation spreadsheet if you were so inclined to see the data:
7427

7428

7429

Check out this page: https://www.pirate4x4.com/threads/the-b ... t-44988271
It's not the only resource I used for my calcs... but I did lean on it for most!

And, again, sorry about switching between metric and SAE units so freely!

John
You do not have the required permissions to view the files attached to this post.
faux40 Offline

User avatar
Administrator
Administrator
 
Posts: 1206
Images: 1310
Joined: Sun Jul 28, 2013 12:45 am
Has thanked: 635 times
Been thanked: 1116 times
Location: Roseville, California

Postby faux40 » Thu Oct 22, 2020 1:42 pm

Okay, everything is in the shopping cart. Double checking everything... DOH!

This morning I was withing 30-seconds of clicking buy on all the parts for my super-duper disk conversion when I decided to just double check a few things. I made an awful discovery... Nissan Frontier lug circle diamter changed in 2005! It went from the truck standard (including the Patrol) of 5.5" diameter to a smaller 4.5" diameter! Dangit!

I was hopeful that I'd be able to use the brakes wholesale from another Nissan vehicle - and I still am! But I'm kinda thinking that it will be a mix of parts from two or even three different vehicles.

To quote one of the best movies ever... Never give up, never surrender!

John
faux40 Offline

User avatar
Administrator
Administrator
 
Posts: 1206
Images: 1310
Joined: Sun Jul 28, 2013 12:45 am
Has thanked: 635 times
Been thanked: 1116 times
Location: Roseville, California

Postby faux40 » Thu Oct 22, 2020 8:19 pm

Well - I pulled the trigger. Sadly, it's not all Nissan... but it is MOSTLY Nissan parts! Not to say I can't change my mind later and return the stuff, but here's what is on the way:



























Part Vehicle I am pilfering it from Cost/Source
Front Rotors 2003 Chevy Silverado 4x4 $31 each on Amazon
Rear Rotors 1995 Nissan Pathfinder $26 each on Amazon
Front Calipers 2016 Nissan Frontier SV $126/pair on Amazon
Rear Calipers 2016 Nissan Frontier SV $91/pair on Amazon
Front & Rear Pads 2016 Nissan Frontier SV $36/set on Amazon
Total cost (so far): $367


When it comes time, I expect to use a master cylinder with a 1-1/8" diameter piston along with a smaller vacuum booster in order keep the pedal pressure in the target range. I calculated the required effort using no booster, a 3:1 booster (on the smaller side), the stock brake pedal with a 7:1 ratio, and a modified brake pedal with a 5.75:1 pedal ratio (which may require tipping the MC rearward a bit to maintain the proper MC push rod geometry).

From what I've read, typical foot pressure is in the 50 to 75 range. Lower than that and the brakes will be touchy. Higher and you may not be able to press hard enough to get the max rate stop. The yellow highlights the combinations that seem to work best.
7431

I've tweaked the spreadsheet to reflect my choices... but it's nearly the same as what I posted earlier.

John
faux40 Offline

User avatar
Administrator
Administrator
 
Posts: 1206
Images: 1310
Joined: Sun Jul 28, 2013 12:45 am
Has thanked: 635 times
Been thanked: 1116 times
Location: Roseville, California

Postby jwgreen » Thu Oct 22, 2020 9:07 pm

A CHEVY ROTOR :shock: :o :o :shock:

That's not very NISSAN of you John!!!!!!
Justin
jwgreen Offline

User avatar
I love driving my Patrol!
I love driving my Patrol!
 
Posts: 913
Images: 70
Joined: Thu Oct 24, 2013 11:23 am
Location: Iola, Tx
Has thanked: 94 times
Been thanked: 541 times
Location: Iola, Tx

PreviousNext

Return to Projects

Who is online

Users browsing this forum: No registered users and 0 guests