[TonyBG]

Hi guys,
bad new for me From the last couple of hundred kilometers I have a squealing noise coming from the back of the car which goes louder when I am moving faster. Soooo...today I went to the garage....and the "judges" said: Rear Differential. Almost make me cry since it goes around 2000$.

I am driving the Jeep Compass 2007 2.0 TD diesel.

So i started look around to find cheap genuine parts store, or an used one. And I encounter the following problem: there seems to be several rear differentials for Compass/Patriot/Caliber. At Mopar page I see 2 types of differentials, this one:

http://www.mopar.com/part/3501A115?s=288297&i=870301&b=jeep

with a part number: Part # 3501A115

and this one:
http://www.mopar.com/part/3501A058?s=288297&i=870300&b=jeep

with part number: 3501A058

It says both fits Patriot/Compass....but there seems to be a difference I cannot understand. Is it had to do with the transmission (manual or CVT)? With the gear ratios?! Also I have find on ebay some used one saying. With or without Low Gear. What this Low Gear means?

I will be very thankful if somebody can answer my question, cause I am in the dark in that matter. Thank you in advance!

 

[FujativeOCR]

The Low Gear comes on the Patriot w/Off Road package. It's an extra low ratio you can shift into in addition to the CVT. I'm not sure that was an option on the Compass?

 

[Urr]

At Mopar page I see 2 types of differentials, this one:

http://www.mopar.com/part/3501A115?s=288297&i=870301&b=jeep

with a part number: Part # 3501A115

and this one:
http://www.mopar.com/part/3501A058?s=288297&i=870300&b=jeep

with part number: 3501A058

I would guess that 3501A115 is the one you need, as you have CRD Compass, probably 4WD.

The other one is only for Patriot 4WD.
In 2007 only Patriot had Freedom Drive II with Low Gear, but not Compass, it must have something different and it concerns this low gear.

 

[TonyBG]

10х a lot for the quick response guys!
I also tried to search for some Patriot used one and i found a damaged 2009 Patriot, with VIN: 1J4FF28B29D106718
and I`m trying to figure it out, is it gonna fit on mine.
FujativeOCR you r right, is not an option for the Compass and probably its not gonna work for it.
So then 3501A058 is not an option....but is that mean that any from the Patriot without the Off-road package will work?
Urr you are right i got the Diesel with manual shifting. Does the rear differential depends on the transmission, or it dosnt matter.. I mean 1 from a CVT Compass/Patriot will work on the manual?

Thanks again guys!

 

[Gramps]

I only have the parts books for '07 & '08 but believe that there were no changes for the later years. The CVT, T355 5 speed (petrol) and BG6 6 speed (diesel) all take the same rear axle assembly - 3501a115.

The other is listed on the FD II off road package only.

 

[TonyBG]

Great! 10x Gramps! So I am looking for this differential. Also if I searc for used one Patriot is also an option....except...one with an Offroad Package.

10x a lot guys!

 

[Gramps]

Correct. I do believe that the off road package was not available in the EU so anything local should work fine. All MK's had the same Rear Differential (except the FD II).

 

[TonyBG]

Oh, there is no way I am going for european parts))
I will try to find something used on the american ebay, since here a differential will sell for around 3000$
So I`ll probably try and find something used over there and shipped it here. But now when I know Patriots are also have this differential my search range will expands

 

[TonyBG]

When I think about it.....we are so ****ed up here, when it comes to parts for american vehicles. The dealers are ripping us, so we try to ship but price is = ((price of the part + shipping to Europe)x1.1tax)x1.2 VAT and you got the final price

 

[Brywalker]

Correct. I do believe that the off road package was not available in the EU so anything local should work fine. All MK's had the same Rear Differential (except the FD II).

Soooooo what would happen if you installed the FD II differential into a FD I Compass/Pat?

 

[Gramps]

Oh, there is no way I am going for European parts))
I will try to find something used on the American eBay, since here a differential will sell for around 3000$
So I`ll probably try and find something used over there and shipped it here. But now when I know Patriots are also have this differential my search range will expands

I was just saying that ALL of the EU parts would fit and the vast majority of N.A. parts will fit too. Maybe as high as 80% of them. The FD II, although well liked for its off road capabilities, was not the popular option.

When I think about it.....we are so ****ed up here, when it comes to parts for American vehicles. The dealers are ripping us, so we try to ship but price is = ((price of the part + shipping to Europe)x1.1tax)x1.2 VAT and you got the final price

Ya, VAT sucks. So much for free trade!

Soooooo what would happen if you installed the FD II differential into a FD I Compass/Pat?

Just like any other 4WD vehicle the front gears need to match with the rear gears. It's the final drive ratio up front that determines what you need in the back. The wrong one would totally screw up your ESP, traction control and braking. You'd be totally screwed.

 

[Brywalker]

Clearly I know nothing about this.

 

[Gramps]

Everybody's a virgin at one time so hang in there and I'll try and explain this without being too detailed or oversimplifying. It actually can get very complicated.
When taking a corner in a 2wd vehicle the outer wheels turn faster than the inner wheels because they have a greater radius to turn so you have the inner wheels sliding and not gripping. Having 4wd doubles the problem. Manufactures compensated for this in the early days by making the front and rear differentials with slightly different ratios, say 4.10:1 and 4.11:1 to compensate for slippage. Add in to that a gear box to connect the front to the rear and that let a little bit of variation in torque delivery to help out too.
Enter the electronic age with ESP that includes traction controls and individual braking on each wheel that is controlled by sensors. This helps to eliminate the slippage. Our Patriots and Compass' also use a viscous coupler that allows more flexibility than a gear box too so we gain some on drivability from that.
Still with all of the electronics to help out the front and rear differentials need to be close enough in ratios to be able to work together or the sensors would not be able to keep them 'in sync'. The difference between the FD I and FD II final drive ratios is too much for the ESP to handle, 6.12:1 vs 8.15:1.
Now to throw in a sticky wicket that I can't answer - the 5 speed has a final drive ratio of 4.12:1 but is the same unit as used on the CVT.
I do not now the actual drive ratio of the rear axle, this info is all from transaxle specs.