colsoncj

So I was lookin around the Marlin Crawler site, and noticed that there are complete 3rd-members for sale. I plan on putting 33's on the truck, so a re-gear is in order. I also figured that since I'm regearing, detroit lockers probably aren't a bad idea.
Heres a link:

http://www.marlincrawler.com/3rd_pickup.html

So here's the questions:
I don't have the tools to do a regear, but I believe I can install a complete 3rd member. How hard is it? Will I need anything special?

The prices are $899 an axle. Considering these are rebuilt units with all new parts, pricewise is that an acceptable deal, considering the component costs and rebuild labor costs.

If I do buy a front detroit locker 3rd member, and later decided to swap in a 85 solid axle, are they interchangable... can I put the locker unit in the 85 axle?

Thanks to all for the help!

kyle_22r

i think the price of $899 for a third setup with a detroit and your choice of gears is about the going price. i think a detroit runs around $400, gearset is around $200, and the master install kit is about $100. you're getting a whole new chunk so i think that'd take up the rest, plus install time.

what gear ratio are you planning on getting? if you'd like 4.10, 4.30, or 4.56, you may want to look into an E-locker. they run about $795 out the door for the whole third from toyota. the only thing you have to do is have the housing modified and wire up the switch

also, IFS fronts and SFA fronts aren't the same. the IFS uses a 7.5" gearset while the SFA uses an 8", interchangeable with most 4x4 rear axles

crawler#976

it's very simple to install a new third into a rear axle.

1. support the vehicle on jack stands

2. remove tires

3. remove brake lines and cap off lines

4. remove the four nuts off the axle flanges

5. remove the axle shafts/backing plates/drum assy

6. disconnect the drive shaft

7. drain the third

8. remove the nuts from the studs on the axle housing around the third

9. I use my jack to "bump" the third loose from it's gasket

10. remove the third- be carefull- it's heavy. I use an old milk crate to support the weight of the third

11. clean the gasket surface and interior of the housing. I use brake parts cleaner.

12. I don't use the paper gasket. Apply a good bead of red RTV to the housing.

13. install the new third in the reverse order- again, be carefull- it's HEAVY

14. this is a good time to install new axle seals- they are cheap.

15. remember to refill the housing w/ gear oil!

16. bleed the brakes!!!

16. BREAK IN THE NEW THIRD!!!!! Drive 10 to 15 miles, park over night to let it cool down. repeat if you want to. no towing for the first 500 miles. change the diff oil at 500 miles. That is a good time to start using a good synthetic gear oil- it's kinda spendy to use for break in lube.

ABSOLUTELY DO NOT drive your rig without breaking in the gears. The heat will destroy the gear set- been there done that.

This sounds more complex than it is. It should only take a couple hours start to finish for a rear axle. A front axle is a lot more involved tho.........

I just pull my front third last Saturday afternoon- took about 6 hours total to do relube wheel bearings, knuckle bearings, and birfs, only to find a broken pinion gear. I'm installing a new rear third this Sunday, ans swapping the old rear to the front over Labor day. At least I won't have to spend the time on bearings and birfs again..........

colsoncj

I remember that the front IFS is a 7.5" gearset, while the SFA is a 8". My question is can a 8" gearset fit into the IFS 7.5" housing?

I also plan on using a 4.88 gear ratio to offset the 33's.

crawler#976

NOPE!

colsoncj

Does anyone know of a reputable place to get a complete 3rd member for a 7.5" with 4.88's and a detroit locker? Preferably around the 800 to 900 range.

colsoncj

Crawler, I wanted to say thanks for the great write up on how to change out the third, along with the rest of the advice you've given... its greatly appreciated.

anthony1

iTrader: (1)

You can probably find a 4.88 7.5 third at the junk yard. the auto with 31's option came with them. You can go a lot of places with just the rear locker. when you decide to do SAS then get the front 8" hi-pinion with ARB third. The detroit is good but it makes it harder to turn in the front.

the goal is to not to spend more than you have to in the front if you're gonna go SAS later.

colsoncj

I do plan on going to a SAS one day... but not in the immediate future, and the more I think about it, probably not with this truck. I see keeping this IFS for long enough to justify putting money into the IFS. However, I'd like to find a complete ready to go and drop in 3rd with all the goodies.... But if I have to track one down and have it rebuilt I will, I'm just tryin to save time. I have a week to get a lift kit installed, and change out both axles, new rims and tires, and hopefully have a little free time.

anthony1

iTrader: (1)

If you have a buddy with Detroit up front, drive his truck to see if you're ok with the way it turns. ARB is ideal for the front.

colsoncj

I had someone mention to me that detroit doesn't make a locker for the IFS 7.5". Any ideas? I've also been told just to go with a lock-right up front. I've been talking to someone else and they've had one up front for a few years and are quite happy with it.

colsoncj

Another question: Since I don't plan on putting an ARB up front, whats the opinions on leaving the front diff open, as not to side walk with the front end?

anthony1

iTrader: (1)

hey, I just notice this is your dd also.
I fyou get snow, you might want a switchable one like ARB or Toyota elec. locker.
I ran with open front and locked rear detroit for a while. I didn't like the way it behaved in the snow though. slide all over the place. Especially in a bank turn going too slow.

colsoncj

Can you get an e-locker for up front? If so where do you get one at, about how much does it cost, and how hard is the install?

colsoncj

i know Kyle mentioned getting them from toyota, but do they offer them as a whole third with 4.88's?

anthony1

iTrader: (1)

the toy elocker is 8" so it would not fit the IFS housing. ARB makes one for the 7.5 diff though.

colsoncj

Anthony, thanks for the input, I appreciate it. And just so I didn't forget anyone, Kyle, thanks to you too. It makes a huge difference going into something like this when you have the great knowledge background that you guys have shared. When I get all this stuff put in, I plan on doing a tech write up. Anyone know who I should talk to about getting it posted on the site, or if the site would be interested?

crawler#976

edited the list........moved the draining to #3

1. support the vehicle on jack stands

2. remove tires

3. drain the third

4. remove brake lines and cap off lines (I use vacuum line plugs over the ends to keep'm from draining all the fluid out of the system)

5. remove the four nuts off the axle flanges

6. remove the axle shafts/backing plates/drum assy

7. disconnect the drive shaft

8. remove the nuts from the studs on the axle housing around the third

9. I use my jack to "bump" the third loose from it's gasket

10. remove the third- be carefull- it's heavy. I use an old milk crate to support the weight of the third

11. clean the gasket surface and interior of the housing. I use brake parts cleaner.

12. I don't use the paper gasket. Apply a good bead of red RTV to the housing.

13. install the new third in the reverse order- again, be carefull- it's HEAVY

14. this is a good time to install new axle seals- they are cheap.

15. remember to refill the housing w/ gear oil!

16. bleed the brakes!!!

16. BREAK IN THE NEW THIRD!!!!! Drive 10 to 15 miles, park over night to let it cool down. repeat if you want to. no towing for the first 500 miles. change the diff oil at 500 miles. That is a good time to start using a good synthetic gear oil- it's kinda spendy to use for break in lube.

ABSOLUTELY DO NOT drive your rig without breaking in the gears. The heat will destroy the gear set- been there done that.

_____________________________

As to lockers and snow, it just takes a little getting used to'm.

When we do get snow, it usually starts at temps around 38 degs or so.........and when it finally does drop below freezing, we get ice w/ a layer of snow on top. I drive a full spool, and find that you just have to be a bit more carefull on planning turns. A locker tends to push you straight ahead even if your tires are turned, so I use a "little" throttle to get the rear end to come around. It doesn't take much.

And of course, lockers in deep snow are a blast. Nothin' like just cruzin by people stuck on the Forest Service roads- passing a vehicle stuck in 10" of snow by taking the ditch is kinda fun We ran thru 26" of pretty heavy snow with not too many problems-

Robinhood150

Check pirate for used 3rd members with the gearing you want. I got a V6 3rd with brand new gears and ARB for $1000.

As for a writeup, we've got everything from how to change oil to an SAS and dual transfer cases. Any writeup is welcomed. There are some rules which can be found in the tech writeup section. When you're done, contact Corey.

kyle_22r

you can get one specially for the front, but only if you have a straight axle. 80 series(and several other good ones we don't get here) land cruisers have a hi-pinion third member in the front, it's a drop in replacement for a stock straight axle third. it's available with an electric locker just like the TRD rear one, you have to do the same mods to the front to install it as you'd have to in the rear(tap new holes for studs and clearance the pumpkin)
nope i really wished there was a 4.88 option, but 4.56 is the lowest that the locker is available with from the factory. however, it can be regeared with any V6 gearset, but there's a big price jump going from 4.56s($795) to say, 4.88s($1200)