Rear Gears

I have an '06 Tundra with an open rear end. It's either a 3.7 or 3.73 now. I'd like to have a "posi" 3.73 third member installed. What would be the price for something like that, and where or who would reliably do the work...at about what cost. Open rear ends just don't cut it when ya live on a hill where it snows in the winter.

 

I’m changing my third member soon too. My current one is on its way out, I have a clunky 4.03. Luckily my buddy is putting a 4.10 third in his and I’m going to get his 3.93(I think) With lsd.

You can find used transmissions with lsd. But I don’t know how to check an lsd without taking it apart Or driving the vehicle, so I don’t really feel comfortable buying used. The only reason I feel comfortable buying this one is because it’s from a family friend so I’m not worried. The used ones I was looking at were priced from 400-1500.

I was also looking at Eaton Truetrac lsd, they’re supposed to be reliable. I think I’ve heard the auburn brand ones aren’t bad either. Both are about 5-600 brand new if I remember correctly. Detroit locker and arb are popular too, but I was just looking for a lsd.

as for cost of work, I wouldn’t look for a discount on this job. Find some who knows how to work on differentials, not someone who thinks they can. If you have tools and you’re handy it’s not the hardest job in the world. But you need the right tools. Watch some install videos on YouTube and see if it’s something you are interested in doing. If not at least you know what you’re going to be paying someone to do.

 

Having a loose 3rd member rebuilt is about $200-250 labor only. Dropping off s truck to have it done will run $400-500 labor only.

To check a diff for LSD on these trucks remove the fill bolt and look inside. If you see gears it's not limited slip. If you see a big cylinder then it is LSD.

 

Good information. Thank you. One question though: What is "LSD"? I mean, back in the 60's and 70's I knew what it was. But for a Toyota truck I have no idea.

 

Limited slip diff.

 

Thank you.

 

"To check a diff for LSD on these trucks remove the fill bolt and look inside. If you see gears it's not limited slip. If you see a big cylinder then it is LSD."

A few months ago I had the rear of the truck off the ground with a jack. Turned one wheel one direction and the other rear tire/wheel turned the opposite direction. If the tires/wheels turned in opposite directions wouldn't that indicate that it's an open rear end and not an LSD?

 

My wheels do the opposite thing you describe. Also, my truck is equipped with LSD per the VIN#. I haven’t peeped in the chamber for the Magical Drum to confirm though.

 

I don't trust this method, I've heard mixed results on it.

 

Or the person who had it before you liked to drift and do burnouts all the time and The lsd no longer works correctly.

 

Okay, I'll have to get out there and pull that plug and take a look inside. One way or the other I'm gonna have a limited slip rear end. Thank you all for helping me.

 

What part of the VIN tells the story if it's limited slip or not?

 

If it’s factory LSD the rear axle should have a little sticker near the full hole that says LSD oil only

 

No tag there. Looks like there was never one there. I'll have to get out there tomorrow and pull that plug and take a look. I'll be back.

 

Jack up the rear axle and spin a tire. If it spins opposite on the other side you do not have an LSD.

if you want a full locker there is the powertrax lock right, slides right in

 

Cool. Thank, Hbjeff

 

Mine spin different directions... but the LSD definitely still works... typically they are suppose to spin the same direction though.

 

how strange

 

That's why I don't recommend that method. Crawling under and pulling the fill bolt is much easier anyhow.

 

Mine does the opposite spinning on the other side. My VIN# has the LSD noted and my diff has the LSD Sticker. I have not confirmed the Magical Drum in the Plug Hole visual test though. Have owned truck since new.

 

How would one know their LSD is still "working"? Curious what you guys are experiencing.

 

When I see my wife and shes doing this

 

You didn't say if you had 4x4 or 4x2, but the specs from the 2006 brochure should tell you if what rear-end gearing you have...the first pic if 4x4, the second 4x2. Also, you can register your truck by VIN at toyota.com\owners and usually if it came with an LSD it will be listed there under "view specs" and "Factory and Port installed equipment."

If I did not have LSD and wanted one in an FGT I'd go with a TrueTrac. Fairly cost effective LSD option for everyday use and more effective off-road than a typical clutch type LSD if you learn how to work the brakes when needed (all Humvees have torsen differentials like the TrueTrac front and rear) and unlike the clutches, there are no plates to wear out.

https://www.youtube.com/watch?v=JXtHM5-P0s0

https://youtu.be/x40WGUtdaLI?t=366

 

Try a few experiments in a safe area. Try turning on loose gravel from a stop. Turn 90° and give it some gas. If one wheel only spins and the other does not then bad or no LSD.

Same experiment can be done on wet roads. Its normal for the a slight delay on the lesser traction’d wheel to kick in. Less than a half second.

 

I was stuck in a ditch after leaving my special fishing spot and i remembered this thread, i kept her in 2hi and only one wheel was spinning, was kinda disappointed! Threw her in 4hi and brought her right out after that

 

Yeah. That is a bummer. Only time I’ve ever been stuck was in red sand in 4wd. Dug myself out and moved on.

I know my LSD kicks in on some wet road action on curved on/off ramps at speed. Keeps the tail end from kicking out at speed like a non-LSD truck. Gives controlled drifting action.

 

Yes that is a huge safety issue if one tire kicks out like that. Thats how i wrecked my 2002 tundra 2 years ago

 

FYI: Mine's a '06 Tundra V6, automatic. I've looked up specs which state a 3.7 or 3.73 rear gear, depending what and where I find the specs. Pulled the plug. I see gears. No tag, has gears and tires turn in the opposite direction when only one is turned. I think I have an open rear end. /S

 

Yup, open diff.

Here are some pics borrowed from Zuk's website to show the difference. When looking through the fill hole you would have the area circled in red in your view. The ring gear sits on the drivers side, fill plug is on the passenger side.

Open diff you'll see gears


LSD you'll see the cylindrical body of the carrier