Drive train clunk

[DougC]

I have a slight off idle hesitation from a stop but no sound. Is this similar to what some of you experienced? The engine doesn't stumble but I feel a little hesitation then she's off. Bought the spring helpers and will try them out. When I have the trans in first and take off I don't feel it. Hope it isn't the trans itself.

[bestatchess]

I have installed and tested the JetTech springs. Although I am usually very sketpical about bolt on stuff, particularly cheap bolt on stuff, let me summarize my experience by saying:

Holy cow, these things are great!!! Thanks, JetTech.

I drove around for a couple of days noting my experiences with and without, using a little voice recorder. All of that stuff is pretty boring. To summarize: What people say about these things is true. The only potential negative is that the ride is a bit stiffer. Not alot, but noticeable. Less like a car and more like what you expect from an off-road package truck. A couple of specific highlights:

Every day, I have to turn from a gravel road onto an ashphalt road. The gravel road is inclined in two planes such that the front of the truck is substantially higher than the back, and the right side is substantially higher than the left. I turn right onto the asphalt road, which is pretty steep uphill and banked to the left. Pre-JetTech Springs, this resulted in alot of wheel spin, ABLS engagement, axle hop, more wheel spin. Post Jet-Tech Springs, the scenario is a little bit of spin, ABLS engagement, and immediate launch. The difference is not subtle, but rather dramatic, even startling.

A similar situation involves turning right from an asphalt road onto another asphalt road. The first and second roads are both pretty steep uphill, the first inclines side to side so that the right side of the truck is low, and the second road is pretty level side to side. This situation is such that I must accelerate quickly while making the right turn to cross three lanes of traffic to get in the left hand highway entrance lane on the second road. Human nature being what it is, there are always a couple of people who want to block, so more often than not, this results in a bit of a race. Pre-JetTech Springs, this resulted in wheel hop and alot of tire squealing. Post JetTech Springs, this results in immediate launch with no tire squealing.

All of this started me thinking (I need to start thinking all of the time like JetTech), that the cure is the result of the helper spring resisting the longitudinal (parallel with the truck - fore and aft) deflection of the stock leaf springs to prevent the deflection shown in JetTech's diagram. I then searched for the conventional traction bars and noted there is nothing for the Titan. However, I did note that some of these conventional items have a coil spring / shock absorber component that appears to be oriented longitudinally, to resist the aformentioned fore and aft spring deflection. I was wondering if that type of arrangement (if anyone ever made if for the Titan) might cure the axle windup problem, without stiffening the ride? (As a downside, those seem to cost about 10 x JetTech's solution).

Another couple of side points: As far as painting or powder coating: That would look nice, but by the way my stock springs are flaking & starting to rust, I think that will result in helper springs looking alot better than the stock springs in a short period of time.

On the front helper spring bracket: My first impression was that the front bracket is a little cheesy. When I thought about it, I realized that there is almost no load on the front bracket, but rather the nylon pad bears the load. So yes, a nicer bracket would be good, but I don't think that important to long term function.

[Masa]

First of all, thanks JetTech for the tips about hunting down the rattle source. Secondly, Bestatchess, thanks for the great detailed report! Well, I finally called 800-Nissan 5 about my drivetrain thump problem just so they will have it on their record. To my surprise, I was told Nissan is aware of the problem and working on the fix right now. That was encouraging since I was expecting to hear something like, "We've never heard of this." or "That's normal for a full-size truck." BTW, those were what I was told by the dealership... The Nissan customer service rep couldn’t tell me how soon the fix will become available. I guess JetTech was already in contact with Nissan about this earlier, but it's nice to know they are publicly acknowledging the issue and promising to come up with a solution.

[JetTech]

Originally Posted by Masa

First of all, thanks JetTech for the tips about hunting down the rattle source. Secondly, Bestatchess, thanks for the great detailed report! Well, I finally called 800-Nissan 5 about my drivetrain thump problem just so they will have it on their record. To my surprise, I was told Nissan is aware of the problem and working on the fix right now. That was encouraging since I was expecting to hear something like, "We've never heard of this." or "That's normal for a full-size truck." BTW, those were what I was told by the dealership... The Nissan customer service rep couldn’t tell me how soon the fix will become available. I guess JetTech was already in contact with Nissan about this earlier, but it's nice to know they are publicly acknowledging the issue and promising to come up with a solution.

"When" is my problem with Nissan. Someone here on this forum was tracking Nissan lurking here, I think there is a small possibility that Nissan is taking notes on some of these issues that are posted, or maybe I'm just dreaming...

[mtbendo]

Put them on yesterday and here's another benefit: those freeway problems with the Titan rocking and rolling along on the pavement we have here in California is now not a problem anymore. These things stiffened up the rear enough to dampen the bounce created when going over these uneven surfaces at cruising speed.


37L1, you got to be kidding me. I would have thought it would have been the other way around! I was thinking of replacing my rear shocks with adjustables to soften things up but now... It's bad enough on the freeway that I've noticed I can't keep my foot on the pedal at the same position because it rocks so bad. For under $30 I'm gonna give it a try! Thanks for the tip.

Actually, now thinking about it, I wonder if it stiffens the suspension enough to change the natural frequency of the suspension so you don't get the oscillations. I wonder if you'd get the oscillations at a high speed?

[vansd1]

Well i just installed mine yesterday. they work great!!! quick question for anyone especially jet tech. if i wanted to stiffen the ride up even more it says to add the little rivit to the hole closest to the mounting point. will this also lower the vehicle slightly more than if i didnt use it or will it raise the vehicle?
just curious because i am thinking about adding it and i want it to drop the back more. i think it should but i am not positive....any comments?
thanks

[JetTech]

Originally Posted by vansd1

Well i just installed mine yesterday. they work great!!! quick question for anyone especially jet tech. if i wanted to stiffen the ride up even more it says to add the little rivit to the hole closest to the mounting point. will this also lower the vehicle slightly more than if i didnt use it or will it raise the vehicle?
just curious because i am thinking about adding it and i want it to drop the back more. i think it should but i am not positive....any comments?
thanks

The lowering of the truck comes from when the U-Bolt is tightened down thus squeezing the springs together. I don't think adding a rivet will lower it anymore but it should resist deflection more if your looking to tighten things up.

[jeff7777]

Excellent Mod JetTech! I installed a set yesterday and the clunk is gone. The truck also handles much better especially in cornering. I did use the rivet (in the "tightest" setting) when I installed the springs, although I am not sure how much of a difference it makes in this application. Either way, they are great!

[scubakleev]

Originally Posted by JetTech

The instructions will give you a basic idea of how to install them but there are several steps that are not needed. You don't have to remove your tires to install them. Just crawl under the truck and bolt them on, if your wondering just where to place them refer to the pics I've attached. I can't say enough good about them and the difference they've made with my truck. Yes I could wait a couple of years until Nissan "might" address this but that's not me. I'm not going to be aggravated by a clunking twisting rear-end for the next couple of years on the hopes that they will. Sometimes it's best to take matters into your own hands through trial and error looking for a cure to a problem!!

After hearing all the positive feedbacks on this i'm going to have to do this my self now. I just want to make sure of one thing. The truck does have to be jacked up correct? I'm sure it does but I cant be too carefull.
Thanks

[z3axv]

Originally Posted by scubakleev

After hearing all the positive feedbacks on this i'm going to have to do this my self now. I just want to make sure of one thing. The truck does have to be jacked up correct? I'm sure it does but I cant be too carefull.
Thanks

No need to jack it up.

[htn123]

Ok,
I installed it yesterday afternoon, just crawed under and bolted it on, took about 30 minutes total for both side.
Question for all.
1. How tight should I turn the U bolt? the more I turn, the more the leaf springs get compressed. I installed infront of the axle toward the front of the truck as other suggested.
2. On the front of the helper, installed on the front of the axle, there is some space between the helper plastic part and the truck leaf spring. Is this normal?

Have not noticed this but after I installed the helper, while foot still on brake, shift from park to reverse, now can hear some sounds like the leaf springs are being squeezed against one another. Normal?

Thanks

[bestatchess]

Tighten the U-Bolt all the way. I think that this will close the space between the factory spring and the front bracket bearing pad and may also stop the noise that you are hearing.

[rvandam]

Just installed mine.
Have only taken a short drive through the neighborhood, but I can already feel the difference. The annoying rubbery feeling when coming to a stop and taking off from a stop is gone!

I do have some questions on the install (bear with me, I'm not too hands-on technical):

1. When tightening the u-bolt, parts of the washer broke off. Problem?
2. How far do I tighten the u-bolt anyway? Tighter = stiffer ride?

Also found a new use for my wireless network: taking the laptop outside with JetTech's instructions on screen while I worked on the mod (running off the 12V connection in the bed)

[TriKKy]

I dont get any thump...lucky I guess? That would really piss me off though.

[htn123]

rvandam,
That is so funny, I did the exact same, took my wireless laptop out and actually go to jettech pictures site to compare the pictures with my installation.