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  1. Tire Chains
  2. pewag
  3. Tire Chains
  4. On Road Only
  5. Deep Snow
  6. Automatic
THIS ITEM IS NOT A FIT FOR
2018 Ford Explorer
pewag

pewag Servo RS Tire Chains - Diamond Pattern - Square Links - Self Tensioning - 1 Pair

Part Number: PWRS77
In Stock
$201.04
Tire Chains
Not Confirmed to Fit

2018 Ford Explorer

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Just make connections and drive - these chains will automatically tension with the flip of a switch. Provides consistent traction in snow and light ice for your vehicle. Diamond pattern delivers a smooth ride and square links bite into ice. Great Prices for the best tire chains from pewag. pewag Servo RS Tire Chains - Diamond Pattern - Square Links - Self Tensioning - 1 Pair part number PWRS77 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (182)
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pewag Tire Chains - PWRS77

Highlights

  • Custom Fit for Your Vehicle: Chains made to match your tire size for a snug fit
  • Quick One-Step Mounting: Just connect and flip the switch—chains tension automatically as you drive.
  • Solid Grip on Snow and Ice: Diamond pattern with 3.2 mm square links bites in for steady traction.
  • Smooth, Centered Ride: Self-centering design keeps chains snug and balanced for less vibration.
  • Built for Tight Clearance: SAE Class S compatible—needs only 15 mm of internal space.
  • Long-Lasting Strength: Titanium-alloy steel resists rust and wear for repeated winter use.

Features to know about

Tackling Steep, Snowy Roads: Diamond Pattern Keeps You Moving

When the road turns slick or the grade gets steep, these chains grip with a diamond pattern that keeps traction constant across every turn of the wheel. The square links dig into snow and light ice while keeping the ride smooth, so you stay steady whether you’re heading up a mountain road or dealing with deep slush in town.

No Need to Re-Tighten in the Cold: Servo System Self-Tensions as You Drive

Getting out of the car to stop and retighten chains is the last thing anyone wants to do in freezing weather. With these, you don’t have to. Just connect them, flip the servo ratcheting switch to “drive,” and roll forward. The built-in self-tensioning system automatically centers and tightens for a perfect fit while you drive, keeping the chains snug the entire time.

Fitting in Tight Wheel Wells: Class S Compatible Low-Profile Build

If your car doesn’t leave much space around the tires, these are designed to fit where others won’t. They meet SAE Class S clearance requirements with only 15 mm of needed space on the inside. That makes them a solid option for vehicles with limited wheel-well clearance while still giving you dependable winter traction.

Built to Last Through Winter: Titanium Alloy Steel Resists Corrosion

Snow, salt, and moisture can wreck cheap chains fast. These are made from high-quality titanium alloy steel that stands up to corrosion and stays strong season after season. The 3.2 mm square links provide a good bite without making the ride harsh, so you get both durability and comfort when the weather turns rough.

Ready When You Are: Compact Storage and Protective Details

After use, the chains fit easily back into their sturdy plastic case so they’re always organized and ready for the next trip. Plastic bumpers protect your wheel rims, and the lightweight build makes them easy to carry and store. It’s a setup made for drivers who want reliable traction without the extra bulk.

Specs

Fit

  • Fits: 14" - 18" tires (for exact sizes, see below)

Diagram showing SAE Class S tire chain clearance requirements with labeled measurements for distance between tire tread and wheel well (A: 1.46 inches) and between tire sidewall and vehicle (B: 0.59 inches).

  • A: a minimum of 1.46" (37 mm) between the top of the tire tread and the wheel well
  • B: at least 0.59" (15 mm) between the tire's sidewall and the vehicle

Construction

  • Link thickness: 3.2 mm
  • Material: High-quality titanium alloy steel

Quantity

  • Quantity: 2 chains

Warranty

  • Warranty: 90-Day warranty

Note

  • Note: To determine whether you can use snow chains on your vehicle, and how they may affect your ABS/EPS functionality, consult your owner's manual.

Confirming Your Fit

If you know your tire size, you may think you won't need to test fit your new chains. But there are a lot of variables that can affect whether chains will fit your specific tires, including your tire type, the amount of air pressure in the tire, the amount of tread wear, and the tire manufacturer.

We recommend that you order chains as early in the season as possible to give yourself plenty of time to test fit the chains and reorder if needed. This way, you won't be stuck out in the cold later with snow chains that don't fit.

You can test fit these chains in your garage or driveway, but you'll want to wait until there's snow on the ground to actually drive with them. Likewise, if you're out in the snow and come across bare pavement, you'll want to pull over and remove the chains. These chains can cause damage to the bare pavement, your garage floor, or your vehicle if they break from the wear of riding on a harsh surface.

RS 77 pewag Servo RS Self-Tightening Chains - Passenger Vehicles - 14" to 18" Tires

Replaces pewag SMX 77, SMX77, and 37045




These chains fit the following tire sizes:

  • 195/85-16
  • 195/85-16S
  • 205/70-17.5
  • 205/70-17.5S
  • 205/80-16
  • 205/80-16S
  • 215/60-17
  • 215/60-17S
  • 215/70-16
  • 215/70-16S
  • 215/75-16
  • 215/75-16S
  • 215/80-15
  • 215/80-15S
  • 225/55-18
  • 225/55-18S
  • 225/60-17
  • 225/60-17S
  • 225/80-14
  • 225/80-14S
  • 235/40-19
  • 235/40-19S
  • 235/50-18
  • 235/50-18S
  • 235/55-17
  • 235/55-17S
  • 235/60-16
  • 235/60-16S
  • 235/70-14
  • 235/70-14S
  • 245/45-18
  • 245/45-18S
  • 245/50-17
  • 245/50-17S
  • 245/55-16
  • 245/55-16S
  • 255/50-16
  • 255/50-16S
  • 255/60-15
  • 255/60-15S
  • 265/60-14
  • 265/60-14S
  • 275/50-15
  • 275/50-15S
  • 7.00x15

Customer Satisfaction Score:

Ratings & Reviews

4.5

182 reviews
Review sort icon
Just make connections and drive - these chains will automatically tension with the flip of a switch. Provides consistent traction in snow and light ice for your vehicle. Diamond pattern delivers a smooth ride and square links bite into ice.

by:

I just received the tire chains and the tag on the container that spells out the tire sizes they fit doesn't include the tire size I ordered. Its 225/75R 16. What now? We are leaving on a trip shortly and I needed those chains. Please call me asap. Thanks!!



by:

These are for a 2005 Ford Thunderbird and are fantastic! Having had four and all-wheel drive cars for years, these make snow and ice conditions of small issue only needing good driving skills.The ease of installation is perhaps most remarkable taking under ten minutes and drive immediately without any further adjustment. Fit is superb with no impingement in what are very low clearance wheel wells.



by:

These chains are so easy to use and got me out of a few sticky situations last winter - we had an unusually high amount of unforecasted snowfall, and these chains were perfect. I gave this vehicle and the chains to my stepdaughter. Unfortunately, these chains didn't come in my new SUV's size. If they did, I would have bought these again. I did, however, buy my new self-tensioning chains in a similar pattern from the etrailer. I haven't used them yet but great service from etrailer.



by:

I got to test them out for the first time after 4 inches of snow going up a long, steep gravel road full of switchbacks and ice patches in Blue Ridge Mountains. They performed wonderfully and were pretty easy to put on. My only concern are the blue plastic parts that could be a weak point.



by:

We used these chains going up to Truckee and they were the easiest chains we’ve ever installed. Highly recommended!



by:

It was my first time buying tire chains, and I'm glad I got them when I did. Practicing three times was enough to learn to put them on and off quickly. I drove through two blizzards with the chains. I also risked going through snow without them and got stuck, so I had to shovel my way out and try to put the chains on, which was not easy. Eventually, when I got them on, I quickly got out of the parking lot I got myself stuck in. I recommend getting them if you're expecting heavy snow because you can feel the traction, and your confidence level when on the snow is very high.



by:

While installing the chains for the first time, the tensioner on one of the chains broke. Thankful it happened before I was in a snow storm on a mountain. etrailer was great to work with. Issued my return and refund.



by:

These chains are amazing to say the least. 2012 GMC Terrain never needed to put chains on it, but we decided to take it on a snow trip. I have used chains in the past on other vehicles and all have been so hard to put on, on so many different levels. It made me hate to have to use them. Now the Pewag Snox Pro are the best chains I have ever used. WOW!!! They were on in less than 5-10 minutes and then taking them off was even easier. One snap of the lock, a few rough tugs, and pulled forward. Shook them of and packed them back up in the awesome case. Smooth ride considering I had chains on and great traction on snow and ice! I did not know I could love chains so much!



by:

Easy to put on! I have a 2023 Toyota Sienna with original tires 235/60R18 and the pewag RS80 fit perfectly. The pictograph instructions were easy to follow and the chains were quick to get on during my test fit. The instructions being in plastic could be helpful if they get wet and I really like the self tensioning aspect of these chains.

A few notes from the Toyota Sienna manual

1. "Vehicles with 17-inch or 18- inch tires Use SAE Class “S” type radial tire chains....Vehicles with 20-inch tires Tire chains cannot be mounted. Snow tires should be used instead."
-These Pewag tire chains are "s" type and the low clearance fit my 18" wheels easily.

2. "The tire pressure warning valves and transmitters may not function correctly when tire chains are fitted."
-If your vehicle cant read your tire pressure and you have chains on...no big deal.

I really liked the ease with which these chains went on and I'm looking forward to seeing how they perform in the snow.



by:

Fit snugly. Will be a little difficult in the snow but with a pair of gloves on it is doable. The red plastic rim protectors would protect rim from metal on metal contact. However, with my M-sport rims and Pirelli Cinturato P7 tires, the red plastic doesn't even come into contact with the rim due to the extended lip of the tire...but this does mean that the chain touches the outside surface of the tire--see pics. A little off putting scarring the sticky looking surface of the tire...but it is inevitable.

On the inside of the wheel/tire, my concern was contact with the knuckle, strut, end link, stabilizer, etc. It does get close to the stabilizer end link, but doesn't touch...my pictures are shown before self centering while driving...so the spacing to end link would only get greater as I installed in worst case scenario to compare.



by:

I drive a 1996 Corvette and have for the past 20 years - year round. And that makes driving near impossible in Connecticut winters and hilly terrains. Until I got my Pewag chains. When the snow accumulates, on go my Pewags and away I go. Snow covered roads, no problem, up and down hills, no problem. I can put my Pewags on both tires in less than ten minutes and I am good to go. Great product! I highly recommend Pewag chains.



by:

I have yet to actually use them but the installation isn't too tricky or complex. Just make sure to follow the instructions on a dry run or two before you think you'll need them ;-)



by:

These are not easy to install with the wheel on the ground on a VW Jetta. I jacked up the car so there was plenty of room to work, and I could spin the tire to make the needed adjustments. Still not easy, but not bad. They work well, or at least as well as I need them to.



by:

My Mazda 3's tires are right at the top of the size range, 215/45/R18, and the tire chains fit! It was a bit hard to get them on, though. After fitting the chains loosely, we were struggling to lock the final hooks.

To lock the hooks, we ended up using one of the spare chains that came in the packaging to bridge that final 1-2 inches. Then, we drove a couple inches forward (until the we could hear the self tensioner click a couple times), and that gave us enough slack to connect the hooks without the spare chain.

I do not recommend using the spare chain to actually drive, unless they're professionally welded/attached, but they were super helpful for fitting the chains properly.

Image shows the chains mounted and the hooks properly attached, but with the auto-tensioner off.



by:

I am not very handy and have no intention of installing my chains on the side of the interstate myself if I can help it. I chose these because they are self-tensioning and can be put on without laying on the ground to install them. I tested installing them twice at home, so I am ready in case of emergency when I visit the seirra's this winter.



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Great price, fast delivery and a great product. You made buying my Pewag chains an easy decision.



by:

Their customer service is awesome!! They reached out to me via email as soon as they noticed delay and kept me updated on the delivery status, and also followed up after the delivery. We now have the chains we need for winter weather! We are very pleased to finally find the right snow chain for our tire size after looking around for 2 years! (235/40 R19, very little clearance)



by:

These chains were invaluable last winter during our big snow storm and thereafter. They are great chains. The only reason I'm not giving 5 starts is that I previously had pretty much the same ones for the 17" wheels on my last vehicle and the hooking mechanism was better on those. This one is rather difficult to hook together at the first attachment point. Otherwise I would definitely recommend these.



by:

Didn’t fit the winter tires of my Subaru Forester 2018.
But since I but the chains in autumn it was too late to return them anymore.
Customer service was also useless. Asked tu about adequate sizing and they said I should call Pewag.
Actual chains are great quality and easy system.

Jenny N. profile picture

Jenny N.

11/7/2022

You mentioned that they were not a fit for your snow tires. I have a few questions that I would like to ask. What is the size of the tires? Would you be able to send a picture on how they do not fit? Did you reach out to Pewag?



by:

I have never been more pleased with a purchase decision than I am with these snow chains. They fit my car perfectly and were easier to install than I expected. If you have ever used on-ground cable chains, you know there are three connections that must be made, plus any adjustments to the tension device. With these chains, the connections are easy and the self-tightening tension device is impressive. At first I was not interested in this feature, but after using it I can appreciate how it will keep the chains tight and secure. I was also impressed by the design of the carrying case. I expected it would be difficult to replace the chains in the case once removed. Wrong. They easily fit back into the handy plastic case. Further, the chains came with plastic gloves to slip over your your hands (even with winter gloves) to keep your hands and lower arms clean. It's a bit odd to be so excited about a product that I hope NOT to use. But I drive to ski resorts all over the West and encounter chain restrictions often. Although I have all-wheel drive, I don't have snow tires and recent chain restrictions in Mammoth, CA require chains or 4-WD with snow tires on all wheels. Now, I'm actually looking forward to using the chains. I'm so pleased, I may purchase a second set for my wife's car. Finally, etrailer.com was great too work with. Their rep ( thanks Donna!) helped me find the right size chains for my wheels. Thanks so much!

Arlo S. profile picture

Arlo S.

1/26/2018

Very well designed product. Service person was very helpful in ing the correct size. I expect to buy the same brand of chains from you for my wifes car.



by:

Am an elder, live in So Cal mountains. Easy for me, at 74yrs, to install on my 2020 Subaru Forester. Thank you for good product, understandable video and great customer service.


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See what our Experts say about this pewag Tire Chains

  • What pewag Snow Tire Chains Fit 2023 Tesla Model 3 With 235/40-19 Tires
    The correct fit for pewag snow tire chains on your 2023 Tesla Model 3 with 235/40-19 tires are the following: - pewag Servo RS Tire Chains # PWRS77
    view full answer...
  • Speed Rating and Operational Use of Snow Tire Chains
    The Pewag Servo RS Self-Tensioning Tire Chains - 1 Pair # PWRS77 are great quality chains that are not difficult to install. They are made of titanium allow steel which makes them very strong and corrosion resistant. The speed rating for this set of chains is 25-30 mph. This is not just for these chains but is the industry standard. Tire chains are not for use on any roads where the pavement is bare. Using them above that speed or on bare pavement can cause loss of traction and even...
    view full answer...
  • Recommended Tire Chains And Installation On 2004 Toyota Sienna
    In your owners manual for your 2004 Toyota Sienna, the online manual states snow tires or chains are recommended when driving on snow or ice. It states to use SAE class S type radial tire chains except radial cable chains or V-bar type chains. You are to use them on the front tires and are given instructions to not use chains on the rear tires. This is according to page 468 of the online 2004 Toyota Sienna manual. For instance, for 215/65-16 tires, I recommend the 2004 Toyota Sienna...
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  • Recommended Tire Chains for 2006 Jaguar XJ With 235/50r18 Tires
    The Konig Premium Self-Tensioning Snow Tire Chains # th02230k45 are confirmed to fit your 2006 Jaguar XJ Series with 235/50r18 tires and I do not see any issues with this setup. The only thing I would say is that it takes some time to install these chains, so if you don't plan on keeping them installed for a long time then I would go with a different set of chains. I personally would go with the pewag Servo RS Self-Tensioning Tire Chains - 1 Pair # PWRS77 instead. This offers a much simpler...
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  • Does Pewag Tire Chain # PWRS77 Fit 2018 Honda Accord with 235/40/19 Tires
    The Pewag Servo RS Self-Tensioning Tire Chains # PWRS77 that you referenced have been confirmed as a fit for your tire size of 235/40-19. What's more important that the wheel diameter is the overall diameter and width of the tire when fitting the chains and this chain easily fits your tire size.
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  • Tire Chains for a 2008 Volvo S-80 AWD
    When a vehicle owner's manual or manufacturer says something like Use only Volvo approved chains that means they want you to buy them from Volvo or a Volvo dealer when in reality they should just tell you what makes chains approved or not. Basically you will need Class S compatible chains or cables because there is limited clearance between the tires and vehicle components. Also, on your vehicle the chains should only be used on the front wheels. If you are able to turn off any type of...
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  • Availability of Pewag RS 77 Tire Chain for 2019 Tesla Model 3
    Since you are wanting the Pewag RS 77 you actually need our part # PWRS77 as the # PWRS76 is a smaller size.
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  • Recommended Snow Tire Chains For 2017 Volvo V60 With 235/40R19 Tires
    The Thule chains you have are great and unfortunately are no longer being made. If you are concerned about the chains, then I recommend the Pewag Servo RS Self-Tensioning Tire Chains # PWRS77 are great for your application. They only require 15mm of internal clearance to operate and that is Class S compatible for minimal clearances. I wouldn't hesitate to use your current chains if they are in good condition. The Pewag option is a replacement recommendation if your chains are not in...
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Do you have a question about this Tire Chain?


Info for this part was:

Employee Lindsey S
Written by:
Lindsey S
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Laura H
Updated by:
Laura H
Employee Wilson B
Updated by:
Wilson B
Employee Hannah L
Updated by:
Hannah L
Employee Mark S
Updated by:
Mark S
Employee Isabelle B
Updated by:
Isabelle B
Employee Sabrina W
Updated by:
Sabrina W
Employee Dustin K
Video Edited:
Dustin K
Employee Chris R
Video by:
Chris R
Employee Aidan B
Video by:
Aidan B
Employee Adam E
Installed by:
Adam E
Employee Matthew B
Test Fit:
Matthew B

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