I've had my 2006 4x4 for about 8 years, it's been up steep shingle beaches towing boats, towed a transit up a steep hill in the snow, and generally has never got stuck even when I've been a bit silly.

 

Anyways...tried to pull away today up a hill...two nearside wheels on Mud and the two offside wheels on the tar and it just wouldn't move. Just span the two inside wheels. Surely the brakes should be applied on these wheels sending the power to the wheels on tar with grip? Is that to be expected?

 

No warning lights etc and the haldex is certainly engaging as the rear wheel was spinning at the same speed as the front. 

Did you try applying brakes yourself? It is the one potential flaws with the system having open diffs.

 

the most concerning part for me is the haldex takes its power only from the offside driveshaft essentially, so in theory if the front nearside wheel looses traction and offside stays still, there is no power being sent to the rear wheels.

Interesting. I'm tempted to go to the same spot and recreate what happened. I was just surprised having seemingly presented it with much more challenging conditions in the past. I thought the "electric differential lock" should have easily braked the spinning wheels and hence sent the power to the off side wheels which had grip. 

My offside front wheel wasn't rotating at all but the rear was spinning away so power was definitely getting to the rear with the offside front not rotating. 

A one wheel drive Yeti!

 

Does the 4x4 Yeti have EDL?

it’s impossible as this is what your gearbox looks like, basically a front wheeled box with a transfer box bolted to the one driveshaft output flange.
 

if that driveshaft flange isn’t rotating then neither is your haldex, this also depends on what side you drive on I guess, and also what way round the engine is mounted, my TFSI VRS is mounted with the engine on the right (offside) side.

 

it is the reason you have EDL, not sure why yours wasn’t functioning though.

 

 

 

On 07/03/2020 at 20:51, MarkyTDI said:

Interesting. I'm tempted to go to the same spot and recreate what happened. I was just surprised having seemingly presented it with much more challenging conditions in the past. I thought the "electric differential lock" should have easily braked the spinning wheels and hence sent the power to the off side wheels which had grip. 

My offside front wheel wasn't rotating at all but the rear was spinning away so power was definitely getting to the rear with the offside front not rotating. 

I need to eat humble pie 🤣

 

it turns out that the transfer box takes its power from the diff itself, so as long as the diff is spinning so is the transfer box for the haldex unit, regardless of if the off side or near side wheel is spinning.

 

I’ve been doing more research for my 4x4 project and I found some better photos and a thread on ASN and it showed a quattro diff with the larger toothed side to the diff body that interlocks with the transfer case, then a long driveshaft goes through the transfer case through the interlocking part of the diff and into the spider gear of the diff as normal.

I believe this is the same system as the toyota celica gt4 gearbox , if u want to see it taken apart look for "project binky" on youtube.

on one of the lateste episodes they refurb the gearbox and u can see that although the tranfer case is mounted on the side of the box it gets is motion directly from the diff via a long shaft.

I’ve not seen the Toyota set up but this is the pictures from the ASN thread.

here you can see where the diff housing has teeth to interlock with the transfer box

 

 

photo of diff installed into gearbox with the diff housing protruding out.

 

 

now a photo of the transfer box, the inner shaft is the front off side output shaft that runs through the hole transfer box to pick up the off side drive shaft, then larger cog at the bottom interlocks with the diff  housing and give a permeant drive to the haldex unit.

 

Thanks for that, its been an education to me as well.

 

Next I am going to carefully lift both front wheels on trolley jacks with their wheels facing longitudinally and the very carefully engage the drive to confirm that the car tries to move forward, will have to wait for a visit to the UK post quarantine as I only have one trolley jack here.

 

I need to ask the question again does the Yeti 4x4 have electronic differential lock on the front diff?

Edited 10 June, 20205 yr by J.R.