Leaf Springs - Should I replace these?

solracem · May 10, 2016, 09:49 AM

Hey Everyone

I'm no mechanic and am learning as I go (mostly from you guys). I was hoping you could chime in and give me some advice on these pictures.

Should I replace these leaf springs?
Should I just add a suspension kit? I was thinking about adding the Timbren kit in the link below. Anyone used it? Do i need it?

http://www.stengelbros.net/GMRP30HD-Timbren-SES-Helper-Suspension-Kit_p_1371.html

Or, do I need both?

I'm trying to get this bad boy ready for a cross country trip in September.

Any suggestions, help and advice is very much appreciated!

Rickf1985 · May 10, 2016, 10:04 AM

Looks like you are very over loaded, have you scaled it? Your air bags are flat and they will do better than the timbrons but they still will not make up for overload on the axle. It also looks like your axle seals are leaking which means your brakes have oil on them. If that is oil I see coming out of the back of the drum, ot brake fluid. either way attention is needed before driving.

BrianB · May 10, 2016, 10:05 AM

From my experience - my springs looked like yours, so I replaced them (search for the thread here that I started). Once I got the new ones in, they had the same "negative" arch, but maybe not as bad. I also replaced the rear airbags.

Based on that, I would say that your springs are probably ok especially if you have good airbags to help out. I can't speak to the kit you linked to. My only thought is that at $400 for that kit, you could spend $200 more for new leaf springs.

BrianB · May 10, 2016, 10:06 AM

Quote from: Rickf1985 on May 10, 2016, 10:04 AM
Looks like you are very over loaded, have you scaled it? Your air bags are flat and they will do better than the timbrons but they still will not make up for overload on the axle.

Rick - my springs (old, and to some extent the new ones) looked like that. And that is with an empty coach.

Rickf1985 · May 10, 2016, 10:09 AM

Did you notice that the air bags are totally flat and bottomed out? as in no suspension left, metal to metal.

With something this big and heavy it is best to just go to a spring place and have them do th work. They can assess the vehicle and make what you need on the spot.

Rickf1985 · May 10, 2016, 10:13 AM

And all the Timbrons are is basically more rubber snubbers to cushion between the frame and axle. Not a suspension in my eyes.

solracem · May 10, 2016, 10:34 AM

Thanks for the help! Glad I asked

Looks like I'll get airbags on there for sure and possibly the springs.

Any idea what the cost of airbags and re-sealing the axles would cost? Also, is there a jack you guys use to get your rig up? Maybe I can do it myself it's it's going to be too expensive to have someone else do it...

legomybago · May 10, 2016, 11:20 AM

Quote from: solracem on May 10, 2016, 10:34 AM
Thanks for the help! Glad I asked

Looks like I'll get airbags on there for sure and possibly the springs.

Any idea what the cost of airbags and re-sealing the axles would cost? Also, is there a jack you guys use to get your rig up? Maybe I can do it myself it's it's going to be too expensive to have someone else do it...

You already have a great aftermarket addition to your factory leaf rear suspension, just add air to your already installed air bags. Pump them up to 75 psi, check air pressure the next day and see if pressure has dropped, if so, make sure your valve stem inserts are tight, or you may need to spray soapy water on the air lines and look for leaks.
The oil on your wheels could be brake fluid also. You definitely need to find the source of the contaminant before your journey.

legomybago · May 10, 2016, 11:21 AM

That shock doesn't even show signs of being bad. No oil leak

solracem · May 10, 2016, 11:24 AM

Quote from: legomybago on May 10, 2016, 11:20 AM
You already have a great aftermarket addition to your factory leaf rear suspension, just add air to your already installed air bags. Pump them up to 75 psi, check air pressure the next day and see if pressure has dropped, if so, make sure your valve stem inserts are tight, or you may need to spray soapy water on the air lines and look for leaks.
The oil on your wheels could be brake fluid also. You definitely need to find the source of the contaminant before your journey.

Gotcha, that makes sense... I'll try to fill those bad boys up but gotta figure out where/how. As far as the brake fluid goes, you're probably right with that as well. I had to replaced the hydroboost and bleed the brakes. It's probably from that.

BrianB · May 10, 2016, 11:34 AM

Quote from: solracem on May 10, 2016, 10:34 AM
Any idea what the cost of airbags and re-sealing the axles would cost? Also, is there a jack you guys use to get your rig up? Maybe I can do it myself it's it's going to be too expensive to have someone else do it...

I don't know what it would cost from a labor perspective, but it's pretty straightforward what the parts cost if you do it yourself.

A 12-ton bottle jack is sufficient to do the job. You would block the axle after getting wheels off, then jack on the frame between the rear shackle/perch to get room between axle and frame to get a new spring in.

Rickf1985 · May 10, 2016, 05:21 PM

Be aware that those springs may well be 250 lbs. each! And the bolts in the ends seldom ever come out without a major battle. the spring shop would not even try to get the bolt out, they would cut them off and use new ones. The also have jacks to raise the springs up in place, or some guy they call "Bubba" and they keep him well fed and supplied with steroids.

Rickf1985 · May 10, 2016, 05:29 PM

I can see they were ten leaf springs that had two extra leaves added to them somewhere along the line. You need to run that across a scale with full tanks, water, propane and gasoline before getting any springs. You have to know what you are working with first. A little over weight is ok but if you are WAY over as it looks then you are taking a chance on breaking the rear housing right at the differential. I used to run a heavy wrecker and I towed my fair share of motorhomes. These you didn't tow since the rear end was on the ground once the rear broke. You called in the 45 foot low boy! I am not trying to be Mr doom and gloom here bt it just looks way too heavy to me, that is why I suggest the scale. Stengle will need that info before they can give you springs anyway.

DaveVA78Chieftain · May 10, 2016, 08:15 PM

The proper way to work through this is to download the Chevy/GMC P-30 Chassis Front-end Alignment Reference Manual from the members area and check the dimensions.
Ride Height discussed on page 14.
Front Load curve on page 23
Rear Load curve on page 24

This way you can determine if the springs are bad or not.

solracem · May 13, 2016, 09:34 AM

Thanks for all the help and advice!

I was able to get out to the RV yesterday and fill the bags to about 80 PSI. I didn't drive it but, did notice the leaf springs went from a frown to a smile. Checked them today and the pressure was still there.

I'll get it weighed soon and hope that I don't have to do much more to get it on the road reliably.

DaveVA78Chieftain · May 13, 2016, 06:41 PM

QuoteI was able to get out to the RV yesterday and fill the bags to about 80 PSI. I didn't drive it but, did notice the leaf springs went from a frown to a smile.

Only problem with that is the air bags may be over loaded.

Gary Eddy · May 13, 2016, 09:04 PM

Here is my 2cents worth.
I'm a very capable mechanic and when it came to springs, I took it in to a spring shop. Mine was sagging on one side.

We came up with correct load numbers and they just added leaves, bushings,pins and new u bolts. I was ready to replace all springs but when the experts looked at it, it was an easy adjustment.

No air bags to surprise you and blow out.

Just a properly maintained set of original leaf springs (front and back) with the correct number of leaves for the load.

Save your money on other diy parts of maintenance. Let a good spring shop do it right and you will be money, safety and frustration ahead.

Gary Eddy · May 13, 2016, 09:15 PM

Just a note----
I had all four sets of springs repaired and it drives great.

solracem · May 19, 2016, 10:28 AM

Quote from: Gary Eddy on May 13, 2016, 09:04 PM
Here is my 2cents worth.
I'm a very capable mechanic and when it came to springs, I took it in to a spring shop. Mine was sagging on one side.

We came up with correct load numbers and they just added leaves, bushings,pins and new u bolts. I was ready to replace all springs but when the experts looked at it, it was an easy adjustment.

No air bags to surprise you and blow out.

Just a properly maintained set of original leaf springs (front and back) with the correct number of leaves for the load.

Save your money on other diy parts of maintenance. Let a good spring shop do it right and you will be money, safety and frustration ahead.

Excellent, I appreciate the advice. It makes sense. I'll go ahead and do that soon.

Jonbbrew · May 19, 2016, 11:52 AM

Quote from: Gary Eddy on May 13, 2016, 09:15 PM
Just a note----
I had all four sets of springs repaired and it drives great.

Do you remember what this ran approx cost?

Gary Eddy · May 25, 2016, 11:10 PM

Yes.
In my case, they removed all springs, cleaned and added some leaves to the back stacks. Front were correct. Replaced all pins, and bushings on all four. New "U" bolts all around. $1,700

That is heavy work for a Diy project and without experience on these issues, you might make mistakes like replacing springs that just needed an extra leaf or two.

That might seem like a lot of money for an old rig. We have lots of big trips under our belt, safety and reliability are worth the cost.

Gary Eddy · May 25, 2016, 11:26 PM

Regarding doing the work yourself on this kind of project-----

See BrianB's post where he installed new springs and they did the same thing.
That is extremely frustrating. And expensive.

I feel sorry for him. We all have those experiences from time to time.

You can always get a quote from someone who does it every day. And then a second one to verify repair options

solracem · May 27, 2016, 04:18 PM

Hey Everyone,

So, it looks like I have 12 leafs. Does anyone know if that's stock for an 89 p32 class A RV? Or do you think a previous owner added springs?

Also, as far as having these replaced/rebuilt, what do you all feel is fair price? I'm pretty clueless here and could really use the help/suggestions.

I was quoted $1,000 to have a couple of leafs added.

Last thing, what weight capacity should I be trying to run on these? Does 4,100 - 4,500LBs springs seem to be sufficient or too small?

This was one of the options I was looking at but, it's less leafs.
http://stengelbros.net/22-419HD-Special-Heavy-Duty-Leaf-Spring-Assembly-Made-in-the-USA-for-69-99-ChevroletGMC-P--Series-Rear--81-Leaf-8360-2ND-1770-4100-Lbs-_p_1836.html

Thanks!

M & J · May 27, 2016, 04:32 PM

You need to have the coach weighed fully loaded where they can give a weight for each wheel plus total. Then call the spring company and give them the details plus coach specifics. Let them determine what is needed.

Rickf1985 · May 27, 2016, 06:26 PM

As has been said many times now, You have to have it weighed. The springs you are looking at will give you between 8,200 and 9,000 lb. rear axle weight MAXIMUM. What is the rear GAWR on the sticker on your vehicle? Probably higher than that. You want the springs to have a higher load rate than the axle but not too much higher or it will ruin the ride. You also have to check the spring eye to eye length because some of these motorhomes used a different length spring. I had mentioned before that it looked like your springs had already had two leaves added. There are a lot of different things that go into springs. The thickness of the leave is a main factor. thinner leaves means you can use more leave and get a smoother ride but if brute strength is needed then thicker leaves and fewer of them is what you want. You cannot go buy just spring count since different thickness means different spring rate. Let me put this in perspective, The springs you are looking to buy are rated at 4100 lbs. That is 50 lbs. lighter than the springs on my 96 Ford F350 single wheel pick up!

That is why I say you need to get it weighed. I went through Stengels chart and that is what a P30 calls for but it does not mention motorhome. The very next year has the ten leaf springs which is probably what you have on there and they are rated at a lower weight, not to mention they have a 5/8 spring eye instead of the 9/16 you should have. If that was changed you will have to see if they drilled your spring mounts or changed the spring bushings. It would have been quicker and easier to drill the mounts so you have to be sure on that. Check the bolt head sizes, a 9/16 bolt will normally be a 13/16 wrench size and a 5/8 bolt will be a 7/8 wrench size.

If you put those springs on and you do not like them then you will be out the money and then you will still need to have a shop do the job. They are not going to give you your money back once the springs have been installed. Also keep in mind all of the other items you need when doing that job, new spring U-bolts. New spring bolts if the old ones don't come out. ( happens a lot). New shackles or frame mounts of old ones are bent or rusted. The U-bolt and spring bolts should be bought new no matter what so just add that into the price. The other stuff, you may or may not need it, they will have it in any spring shop but again, if you find you need it then you are waiting for it to come in.

Looking at how flat those other springs are all I can say is weight it and if it is overloaded you need to get it within the rated weight and then and only then take it for springs.

If you do decide to get the springs and do it yourself and you do find the hole were drilled let Stengel know and they can give you the right springs and put the correct bushings in to match the hole in the bracket, then have them send you the 5/8 spring bolts.