Wednesday, March 4, 2015

DTM5 Update / Blue Glove Tool Review: Eastwood Fender Roller

by CFlo

That's right, the DTM5 is still alive and well. You may remember my black-on-black 1993 E34 M5 from previous posts, but if not, check them out here. Up to this point I've dynoed the car, diagnosed and fixed the fuel delivery issue, shod it with sticky new tires, and straightened out the power seats. Can you guess where this is going? I've been focusing on functionality, with the goal of hitting a local track day in this Autobahn stormer. One major quirk was left unresolved however - a nasty sounding tire rub at the right rear fender lip. Follow along as I fix it with Eastwood's Fender Roller Tool in this multipurpose Project Car / Blue Glove Tool Review writeup.


Ever since my friend bought this car about 8 years ago, the DTM5 has exhibited a nasty tire rub...on the right rear only. It showed scuffing on the corner of the tire where the tread meets the sidewall. This spot rubbed on the fender / wheelarch lip whenever I'd go over any sort of transition, bump, or dip, and was especially bad with passengers or cargo in the car. Ever since I've known the car it's had 255-width rear tires, definitely wider than stock, but not drastically so.


The DTM5 is mildly lowered but it never rubbed on the left side. Who knows why - maybe some quirk of Bavarian semi-trailing arm rear suspension design. Or the fact that this fender lip had been bumped in the past, judging by a localized paint touch-up. Whatever the reason, installing the new meatier Falken RT615k tires exacerbated the rub and made me hesitant to drive on any rough roads or put passengers or cargo in the back. This rendered the car pretty much useless for any purpose except driving to work. The rub sounded much worse than it was but still it had to be fixed.


Enter the fender roller, Eastwood's imaginatively named "Fender Roller Tool" to be exact. Disclaimer: DT is not affiliated with Eastwood in any way, and Eastwood did not provide the tool for review. One of our old friends had it in his garage and let me borrow it. So my out of pocket cost was $0 (well OK, maybe a buck's worth of gas to drive to his place and pick it up), so this is truly an unbiased review.

Botched rolling job pic borrowed from VWVortex.com classified ad

Why would you want to use one of these? There are myriad "traditional" ways to roll fenders, namely the baseball bat or black iron pipe methods. The main problem with those approaches is that the results tend to look hacked unless the rolling technician is an expert. Wavy sheetmetal, cracked paint, and a general air of nastiness are common to most homebrew fender rolling exercises I've seen. In contrast, the Eastwood tool allows you to apply gradual pressure from inside the wheel well without marring the paint or getting stuck between sheetmetal and tire. This tool might be a bit awkward to use on cars with squarish or non-uniform wheel wells; since the tool registers on the hub it works best if the wheelarch is also mostly round and concentric to the wheel. The E34 has flattened roundish rear wheelarches but they are close enough for this to work.

Physically unpossible diagram borrowed from Eastwood instruction manual

Eastwood's tool is made of steel and plastic and consists of three main sections. First is a ring with various bolt patterns to adapt to just about any car's hub, with large brackets welded to one side. Second is the arm and crank mechanism which pivots on the brackets. Third is an arm extension that is adjustable via sliding in the main arm with the roller head and bearings out at the end, at 90 degrees to the arm. Eastwood provides a nice diagram in their instruction manual available here, although the diagram doesn't show the arm pivoting on the bracket - just hanging out in free space (whoops)!

Before rolling - witness mark on the inner fender lip from tire rub

To use this thing, in essence you just remove the wheel, bolt the tool up to the hub, and extend the arm such that the roller is just contacting the inside edge of the fender lip. Then you gradually turn the crank handle counterclockwise, which pulls in the bottom of the arm and forces the top outwards, into the sheetmetal. At this point you want to turn the hub and the entire tool along the arc of the fender lip. The sheetmetal will deform as the roller passes by but will spring back, meaning that lots of repetitions are needed while incrementally cranking the handle to force the roller further and further into the lip for reshaping.

Initial setup angle of the roller

I noticed a few peculiarities when using the tool. It's designed for front fenders "only" but seemed to work well on my BMW's rear fender - but caveat emptor. The hub adapter ring has a central bore to clear the hub, but was too small to fit over the M5's rear hub, requiring use of 4 bolts and a custom spacer wrench to get it secure. The arm and roller tip had to be adjusted frequently to follow the curvature of the E34 rear fender, but Eastwood does warn about this in their instructions (which I didn't read of course). And it did take some elbow grease to get the fender lip to start deforming - but that will be highly dependent on the construction and shape of the particular fender being rolled.

Final roller angle - almost parallel to outer sheetmetal

After about 20 minutes of gradual adjustments and repeated sweeps of the roller, I could see and feel a significant difference in the shape of the M5's fender lip. Instead of a ~45 degree angle between the outer fender sheetmetal and inner lip, they were now almost parallel, meaning that the sheetmetal makes close to a 180 degree bend at the lip. I did not soften the paint with a heat gun as Eastwood suggests but I like to take chances, and the BASF Glasurit paint that BMW used on E34s is apparently pretty resilient stuff. Your results may vary of course, but I was happy with the results. No more cacophonous fender rub making me cringe over every dip or bump.

Custom spacer wrench

The price of Eastwood's tool has recently gone up; when I checked their site in December it was $99.99 but now they show a regular price of $249.99 and sale price of $129.99. A bit over a Benjamin really isn't a bad price if you are going to be rolling several fenders on a few cars with some value.  In addition to Eastwood's site, you can find the tool variously on Amazon  and ebay - with a very wide range of prices.

On an old beater or rusted out daily driver, it might be best to just use a baseball bat or tin snips. The halfway solution is to make a DIY copy of the Eastwood tool with some steel plate, tubing, and threaded rod, as some Renault enthusiast did. An old skateboard wheel should work nicely as the roller, or if you want to get fancy, a turned-down section of Delrin rod with bearings pressed into either end.

You can see the scuffs on the sidewall where it was rubbing the fender - not a problem anymore.

Bottom line - would I buy this tool? Sure, if it was around $100 and I needed to use it several times. It seems well made and should last indefinitely. But for one-time use, probably best to borrow it from a buddy.

All of the Daily Turismo project car posts can be found here. That's right - the DTM5, Draken, Schmetterling and our old 242, all in one convenient link.

10 comments:

  1. Nice post, CFlo! I was not aware of this tool, so I read the details with interest.

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    Replies
    1. Much obliged. Hope it helps with future wide tire / lowering projects. But if you're going to go hellaflush stanced out with super-stretched tires, don't cite me as an enabler!

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  2. My solid rear axle'd 700 series [Volvo] wagons without an adjustable panhard rod out back would always rub when lowered, passenger side closer to the fender lip than left. Not sure about your M5 with its fancy rear suspension though...

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    Replies
    1. It's just your standard BMW fare in the rear...semi-trailing arm, which they used for decades. Not the best but not terrible either. Since the arm's axis of rotation is almost transverse, the rear wheels will travel in an arc as seen from a side view. In other words the wheel will mostly tuck forward when the car is lowered drastically, with a bit of negative camber. The DTM5 had a recent rear end rebuild before I bought it, but that didn't help with the rub, so my best guess is the sheetmetal was slightly tweaked on that side.

      [img]http://www.autopartslib.com/wp-content/uploads/2010/05/BMW-540i-Final-Drive-and-Rear-Suspension-Parts-Components-Diagram..png[/img]

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  3. Fleetwood T. BroughamMarch 4, 2015 at 10:17 AM

    So I like the ingenuity (and the price), but I gotta say this is the "fix" that beauty deserves:
    [img]http://img0108.popscreencdn.com/161421657_bmw-m5-e34-throwing-star-wheels-alpina-3-8-euro-e28-e24-.jpg[/img]

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    Replies
    1. As a '93, this M5 did have throwing stars (M-System II) originally. They are no longer with the car. I likely wouldn't have changed them, but the ACSchnitzer Type II wheels on there now have really grown on me. They are high quality, period correct, and give the car a badass presence.

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  4. Use a heat gun to soften your paint as you roll, or risk cracked paint,

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  5. Oh, before you buy it. make sure it will bolt up to your hub, it didn't on my 70 Ghia project with 130mmx4...got in a spat with who pays return shipping...

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  6. Going into the Eastwood retail store is like being in a toy store for adults. It's incredibly fun and the people who work there are generally very knowledgeable and helpful.

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  7. I'm going to do some shilling for a good friend of mine. If you're interested in rolling your fender but don't want to shell out the money for your own tool you can rent one from http://www.rollyourfender.com. Includes heat gun.

    ReplyDelete

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