Confused about Z71 OEM ft. struts

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dbell54

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Allegedly my 2013 Z71 4x4 Tahoe has Rancho shocks and different springs in the ft. struts, but I can't find anything about replacement strut assemblies specific to the Z71. GM OEM lookup only shows individual parts. Depending on the source used, the shock for RPO 6TJ/7TJ is either 540624/20958798 or 540625/20958799. These are both the correct red color, so may be made by Rancho per OEM. But the only GM assy. I can find that supposedly is correct is AC Delco 903-600RS, which fits most 2013 Hoes. All other brands only have basically one option. No one mentions Z71. Rancho has the RS551784, which is for most. KYB has the SRM4079 Monomax which seems like it would be more appropriate for a Z71, but still isn't specific. Does anyone have any facts? I've spent the entire day researching without anything conclusive.
 

Big Mama

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@915_Tahoe may know the part number. He’ll need your VIN. Another option it to get the shock and have a local shop with a spring compressor swap in the new one.
 

915_Tahoe

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Allegedly my 2013 Z71 4x4 Tahoe has Rancho shocks and different springs in the ft. struts, but I can't find anything about replacement strut assemblies specific to the Z71. GM OEM lookup only shows individual parts. Depending on the source used, the shock for RPO 6TJ/7TJ is either 540624/20958798 or 540625/20958799. These are both the correct red color, so may be made by Rancho per OEM. But the only GM assy. I can find that supposedly is correct is AC Delco 903-600RS, which fits most 2013 Hoes. All other brands only have basically one option. No one mentions Z71. Rancho has the RS551784, which is for most. KYB has the SRM4079 Monomax which seems like it would be more appropriate for a Z71, but still isn't specific. Does anyone have any facts? I've spent the entire day researching without anything conclusive.
What's the last 8 of the VIN#
 

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Allegedly my 2013 Z71 4x4 Tahoe has Rancho shocks and different springs in the ft. struts, but I can't find anything about replacement strut assemblies specific to the Z71. GM OEM lookup only shows individual parts. Depending on the source used, the shock for RPO 6TJ/7TJ is either 540624/20958798 or 540625/20958799. These are both the correct red color, so may be made by Rancho per OEM. But the only GM assy. I can find that supposedly is correct is AC Delco 903-600RS, which fits most 2013 Hoes. All other brands only have basically one option. No one mentions Z71. Rancho has the RS551784, which is for most. KYB has the SRM4079 Monomax which seems like it would be more appropriate for a Z71, but still isn't specific. Does anyone have any facts? I've spent the entire day researching without anything conclusive.
throw those rancho's in the garbage where they belong and get some bilstein 4600's or 5100's
problem solved....
lifetime warranty and they should last you a solid 10 years or lot's more

for what it is worth the rancho's just do not hold up, why gm decided to use them is anyone's guess probably the lowest bidder....
the Bilsteins are highly rated
 
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dbell54

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The Bilsteins don't seem to come in complete assemblies, only the bare strut that has to be installed into the spring. My question is more concerning the spring rate of the Z71 compared to a regular 4x4 Tahoe. All the complete assys I can find fit most Tahoes, can't find anything that mentions Z71 specifically. (No lookup anywhere ever gives Z71 as an option, just LS, LT LTZ, even tho Z71 is supposed to be different.) I'm sure I could put any of those in my Hoe, but are they equal to the stock Z71 spring?
 

blackelky

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The real question is with z71 moog springs and billstein 5100 shocks which setting would it make it cloae to level.
throw those rancho's in the garbage where they belong and get some bilstein 4600's or 5100's
problem solved....
lifetime warranty and they should last you a solid 10 years or lot's more

for what it is worth the rancho's just do not hold up, why gm decided to use them is anyone's guess probably the lowest bidder....
the Bilsteins are highly rated
The real question is with z71 front moog springs which setting on the billsteins would make it close to level.
 

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The real question is with z71 moog springs and billstein 5100 shocks which setting would it make it cloae to level.

The real question is with z71 front moog springs which setting on the billsteins would make it close to level.
you would need to pick some springs, the shock/strut portion really has no bearing on height. Any new springs are going to be higher at least a little bit until they settle.
 
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dbell54

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That's my point, are the Z71 springs taller/different/stiffer than other Tahoe 4x4s? They have their own RPO of 6TJ/7TJ. I don't want to mess with building up a set, I'm looking for a drop-in install that will equal Z71 standards. The KYB SRM4079 Monomax seems like the likeliest match, but I'm trying to get confirmation.
 

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That's my point, are the Z71 springs taller/different/stiffer than other Tahoe 4x4s? They have their own RPO of 6TJ/7TJ. I don't want to mess with building up a set, I'm looking for a drop-in install that will equal Z71 standards. The KYB SRM4079 Monomax seems like the likeliest match, but I'm trying to get confirmation.
just call any dealer parts department with the last 8 of your vin and they can tell you the spring part number needed, then shop them on rockauto/amazon/ebay those will be your best prices.
 

blackelky

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The 5100s have adjustable spring perches
just call any dealer parts department with the last 8 of your vin and they can tell you the spring part number needed, then shop them on rockauto/amazon/ebay those will be your best prices.
 

Doubeleive

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The 5100s have adjustable spring perches
that means you just set it wherever you want
51.jpg
 
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dbell54

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I don't want springs, I need a complete assy. I hope to finish this job in my barn quickly and with a minimum of fuss and tools. Thus my queries about available complete units. AC Delco makes one but it's doesn't specify that it's a match for Z71. Not available from actual GM parts, only the separate parts, which isn't what I need.
 

blackelky

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I don't want springs, I need a complete assy. I hope to finish this job in my barn quickly and with a minimum of fuss and tools. Thus my queries about available complete units. AC Delco makes one but it's doesn't specify that it's a match for Z71. Not available from actual GM parts, only the separate parts, which isn't what I need.
You could get rough country coilovers if you want the whole thing. I just personally like billsteins ride so I will probably swap the rough country coilovers that I have out for billsteins
 
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dbell54

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According to the Rough Country website, they don't make a coilover for a 2013 Tahoe.

Edit: their lookup is crap. They have a "M1 Adjustable Leveling Struts Monotube | 0-2" | Chevy/GMC 1500 Truck & SUV (07-14)" which should work. Why that didn't come up as 2013 Tahoe is anyone's guess.
 
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dbell54

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OK, a little research shows the RC setup is out. It comes preset to 2" lift and to lower it to 0" requires disassembling the strut with a spring compressor. If I was going to do that, I'd just get OEM shocks and install them and save a ton of money. I'm still looking for a drop-in install, quick and easy. But apparently no one can tell me if the available units will work correctly on my Z71.
 
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dbell54

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I emailed KYB for their recommendation and received the following reply:

The question of which product is best for you is dependent on how you use your truck. SR4079 is our recommended OEM replacement for all 2013 Chevy Tahoe 4wd as long as the vehicle does not have electronic suspension, premium smooth ride suspension, or the police package. SRM4079 is a heavy duty performance upgrade that offers increased handling and control for trucks that frequently haul heavy loads, tow, or go off-roading. SRM4079 would also have a firmer ride compared to OE product. If you are not frequently hauling heavy loads or off-roading then SRM4079 may feel too harsh when driving on standard roads with an empty truck bed.

So, since my Hoe has the Z71 pkg, which is already firmer than other Hoes, it leaves me still wondering, but I think the firmer SRM4079 would likely be the safer bet for Z71.
 
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olyelr

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I emailed KYB for their recommendation and received the following reply:

The question of which product is best for you is dependent on how you use your truck. SR4079 is our recommended OEM replacement for all 2013 Chevy Tahoe 4wd as long as the vehicle does not have electronic suspension, premium smooth ride suspension, or the police package. SRM4079 is a heavy duty performance upgrade that offers increased handling and control for trucks that frequently haul heavy loads, tow, or go off-roading. SRM4079 would also have a firmer ride compared to OE product. If you are not frequently hauling heavy loads or off-roading then SRM4079 may feel too harsh when driving on standard roads with an empty truck bed.

So, since my Hoe has the Z71 pkg, which is already firmer than other Hoes, it leaves me still wondering, but I think the firmer SRM4079 would likely be the safer bet for Z71.

I would have to agree.

Did you not ask them for a replacement for the z71?
 
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dbell54

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I would have to agree.

Did you not ask them for a replacement for the z71?
Yes, I pointedly inquired about the Z71 with its specific RPO codes. They apparently have no information in that regard.
 

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