leaf spring replacement

Been chasing a gremlin for quite some time, the annoying thump when I stop. I finally gave up and took it to the dealership and the master tech said it was either driveline or suspension related.

I decided to take it to a transmission shop to find out more on the driveline possibility. The transmission shop test drove the truck and said no it is not in the driveline. They believe it is the rear leafsprings, possibly the bushings but there not really visible but he is confident thats the problem.

I've also suspected this as well because the truck seems to be riding a little rougher in the rear so I am going to replace the leafsprings, bushings, shackels, etc.

My question is can I go with stiffer leaf spring? Does anyone make stiffer springs for this 99 mountaineer or can I get them off of another vehicle?

When I bought new leafs for my 97 I was offered 2 different load ratings, they are stiffer ones. However if you go brand new then it will be pretty stiff.

Isn't the annoying thump when you stop related to the slip joint on the drive shaft?
I think that's well documented on here.

my98nnj said:

Isn't the annoying thump when you stop related to the slip joint on the drive shaft?
I think that's well documented on here.

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Excellent point, but the OP is ...

99 Mountaineer 5.0 2WD 4 door

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The rear shaft does the same (inside transmission).

Still have this problem. I haven't been able to get it fixed because the shops and dealership can't say with any certainty what the problem may be.

Well today I had to hook onto a trailer to tow. I had about 500lbs on the trailer, nothing too heavy. I noticed every time I came to a complete stop, it felt like the rear end was sitting high and when I let off the brakes the rear end dropped.

I also got the thunk at the same time. The way the truck would raise up and settle down so hard has me going back to whether this problem is axle wrap.

So my question is what is the main cause for axle wrap? I've heard that flattening of the leaf springs could do it, but I looked at my springs and they appear to still have an arch to them and their not sitting on the overload spring. Of course this doesn't mean they haven't lost some strength to keep the rear axle from moving.

I really need to fix this. Feeling the whole rear end rise up and settle down to such an extreme has me wondering when something is going to break and cost me a lot of money.

Mystery #2

my98nnj said:

Isn't the annoying thump when you stop related to the slip joint on the drive shaft?
I think that's well documented on here.

Click to expand...

lol If so please direct myself and thousands of others to the resolution! The clunk is in my opinion the second of the two great Explorer mysteries. On this forum, it has been blamed on many things: slip joint, u joint, TPS, SS1, EPC, trans mount, engine mounts, t case chains just to name a few. There are dozens of threads, just no solid resolutions. Many abandoned threads. Best wishes.

It is the rear drive shaft "clunk" (AKA rear axle "clunk"). Happens to almost every vehicle that has a rear shaft.

SoNic67 said:

It is the rear drive shaft "clunk" (AKA rear axle "clunk"). Happens to almost every vehicle that has a rear shaft.

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I only have the one piece drive shaft. According to the transmission shop there is nothing wrong with the drive line.

Like I said, it can move inside transmission end too.
It needs to move in and out because, when rear end goes up and down, length of the shaft needs to change.

SoNic67 said:

Like I said, it can move inside transmission end too.
It needs to move in and out because, when rear end goes up and down, length of the shaft needs to change.

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Ok, what is the fix? I already lubed the slip yoke and that didn't fix the thump.

Well... is worn already. New one?
Tundra does it: http://www.tundrasolutions.com/forums/polls/3074-drive-shaft-thump-clunk-poll/
Lexus does it: http://www.clublexus.com/forums/gx-...lem-with-the-drive-shaft-or-transmission.html
Chevy does it: http://www.tahoeforum.com/showthread.php?t=1307

My truck was diagnosed with some wear at the slip joint too, but it was only a mild clunk on takeoff (it was a 5-speed straight shift), not like you describe.

Have you crawled under the truck and looked at possible worn parts? Is yours the V8 model with the axle wrap bars and 5th shock? Are the main shocks worn out? Trans mount OK?