During the long dark winter evenings my CD of the 2003 Grand Cherokee Manual (plus parts lists for 1999 through 2004 models) is my constant companion.
When WJ owners get together the discussion often turns to how high we can go until we start to have problems with our front drive shafts. Some refer to advice on US websites that say that 3” and even 4” can be accomplished without problems. I have been asked why I bought new drive shafts for "Willie’s Jeep".
If you look at the US parts lists for the different years you find that the drive shafts change from model to model, year to year.
Every petrol Grand that I have seen in the UK has had a Rzeppa to Rzeppa front drive shaft. My 1999 and 2000 V8s both have this kind and the shafts were fully interchangeable. Gary sent me a photo of his 2003 Overland which has the same kind.
Looking at the parts list for a 99 WJ there is only one drawing which is of a Rzeppa shaft although the 3 types, 4.0, 4.7 and CRD have different part numbers.
However, the 2003 parts list shows 2 different drive shafts, a Rzeppa to Single Spicer which is listed for the 4.0 and a Double Cardon to Single Spicer which is listed for the V8.
A Double Cardon shaft is the option offered by Tom Woods for a Jeep with a higher lift which needs more flexibility.
My guess would be that Jeep in the US found that their Grands, which were more likely to face rough terrain, needed the greater flexibility of the Double Cardon shaft while in Europe where they were more a luxury vehicle likely to be used on the school run they found they could stick with the Rzeppa.
A while ago, while making enquiries about 4” short arm lifts from one company or another I was advised that stock prop shafts could be used “depending which model year, trim and engine package the Grand had” but that they would not be suitable if the Jeep was a 99 model. Checking on the Nagca web site finds someone opining that the Rzeppa to Rzeppa shaft is useless for anything above a Budget Boost lift.
I must say that when I still had the original shaft and the budget lift it there did not seem to be much flexibility in the transfer case end joint and that letting the axle drop when the vehicle was jacked up would cause the shaft to bind.
Anyhow for those of you wondering how high you can go maybe this explains some of the confusion.
[attachment=1]
1999 model year
[attachment=2]2003 model year drawings copyright Chrysler Jeep
Tom Woods advises that a Double Cardon shaft should have the single UJ at the axle end and the Double Cardon at the transfer case. The axle should be rotated so that there is no “bend” at the Spicer Joint end and a line drawn through the Diff would go straight up the drive shaft and arrive at a point in front of the Transfer Case where the centre of the Double Cardon Joint is and all the “bend” is here. The higher the lift the more the axle would have to be rotated, this would reduce the caster angle and might make the vehicle more likely to suffer Jeep Death Wobble.
Just a thought.
