Sliding Door Support Roller Refresh FAQ

[Amskeptic]

The sliding door support roller assembly is the main weight carrying assembly, and it yields the biggest gain in sliding door "feel" when you refresh it.
(I have a little secret at the bottom if you successfully get through this)



Step 1 Removal
Grab a bottle jack and adjust it to the approximate height of the door lower edge. Open the door just short of catching the hook. Have your jack at the ready.
Under the door coming up through the roller assembly bracket are two 5mm allen screws with rectangular lock plates. Loosen them a couple turns each. Raise the jack to take some weight, not crazy like. Loosen the 6mm allen screw at the front. You will feel the roller assembly shift as it transfer the weight-bearing duties to the jack. Keep an eye on the upper roller. You do not want it to drop out of the upper track without your awareness and consent. Remove the 5mm screws. Now, babysit the jack/door deal as you remove the 6mm screw.

We need to get the door away from the side of the car just a bit to have the necessary room to run the roller assembly back to where you can pull the vertical roller free of the track. Note that now is the time that you will greet whatever shims have been used to align the door's elevation. Get them off the bracket and put them in the cleaning pile:

Now rotate the assembly 90* (don't scratch any paint on the bottom edge of the sliding door) and release the horizontal roller from its guide (apparently, I do not have the shims off yet):

Lay out your shims and screws and roller assembly. The horizontal roller comes right off its spindle.You can pry the plastic cap off the vertical roller to access its expanding circlip, and remove it and the vertical roller:

Step 2) Clean and Lubricate (and Modify As Needed)
There is a lovely ball bearing in the vertical weight-bearing roller that you clean and lubricate. Now the factory had this lithium sort of grease that dries out and turns into peanut butter over the years. I washed it all out and repacked with Valvoline DuraBlend semi-synthetic molybdenum disulfide grease AND a 1/4 shot of squirt can ATF + engine oil, just in case I should ever find the courage to go north into the cold country ever again. The horizontal roller, I also used Valvoline with a hit of ATF (too heavy a grease causes skidding between the roller and the track). With the cap on, that roller holds the grease/oil just fine.

Below is the bracket upon which your rollers reside:

I filed my bracket skinnier good 2-to-3mm on the underside to prevent contact between the bracket and the painted "floor" of the sliding door track. Even this fresh bus o'mine had the telltale scratches developing on the floor. Normally, you would go to your support roller assembly adjustment, and you would correctly deduce that merely loosening the 6mm screw and jacking the bracket up more vertical-like would lift the bottom of the roller assembly away from the floor of the sliding door track. Yet, sometimes the 6mm screw's captive nut in the sliding door does not allow you to arc the assembly more vertically so the bracket droops perilously close to the floor of the sliding door track:

Step 3) Additional Chores
This is an opportunity to replace the door seal if needed, and it is a good time to rust proof this entire area. There is plenty of road splash that can work its way into the sliding door track area, and the seal running across under the sill can trap water with all the dog hair and detrius that accumulates.
While you're here . . . . . . why not gasoline-wash the grease all out then dry rag wipe and GumOut spray-on-a-paper towel wipe then sand and rust-catalyze prime then paint the sliding door track (and maybe the entire sill if yours does not have the three applications of clear plastic tape scuff-protection that I applied on day-one of ownership)?? That is the door seal wending up over the tool box so I could paint the groove too, because the seal groove can be a real rust trap.

Step 4) Reassembly
Put the clean two 5mm screws, two rectangular lock plates, and the shims if your car uses them, near the rear of the door opening along with the 6mm screw and the wrenches.
Slide the lubricated vertical roller on the spindle with a groove on the roller support bracket. Install the circlip, followed by the plastic cap. Stick the horizontal roller on the remaining spindle and bring this assembly over to the sliding door track cut-out. Carefully negotiate the 90* arc that gets both rollers inserted into the track. Bring the door into position and get the upper roller in its upper track. I used a knee to hold the door here while I got the 5mm screws started, slap in the shims, then the 6mm screw. With loose screws, feel how much movement you have to adjust the position of the door both in the horizontal axis and the vertical axis. I usually "default" to the tightest position I can get, meaning getting the door as high as possible, and inward as far as possible. Hold the door here while you tighten the 6mm not too tight, but reasonably firm. Under the bus, tap the shims in as far as they will go and make a note if the bottom course of the bracket is parallel with the door. You can work a mialigned angle back to parallel, but I recommend a fully involved jack supporting the door while you loosen everything again, and reposition the bracket on the door, then go try to get door high and inward again.
No final tightening just yet. Shut the door. Observe the gap along the bottom of the door from front to rear. Observe the gap along the top of the door. Are they equal? Along the whole length? Nice.
If the gap is not equal, you must determine if the rear striker plate, the rear hinge support bracket, or the support roller bracket, need adjustment.

a) if the bottom gap is small on the bottom at the rear, and the rear striker picks up the door as it closes, the hinge support needs to be loosened and the door picked-up before re-tightening the 10mm hinge support bolts.

b) if the bottom gap is small at the front, either try another round of lifting the door with loose roller support assembly screws then tightening. If no improvement, add a shim.

c) if door edge juts out at the top, loosen the upper roller 13mm nut a bit, and tap the roller spindle towards the door, try 2mm.

P.S. here: adjust the clearance between the upper roller and the ceiling of the upper track at its narrowest point (on my bus, that is very close to the rearmost spot) to 1mm. There are three screws for the upper roller vertical adjustment, AND you need to make sure the roller is exactly perpendicular. You will have nailed it if the roller does not try to climb up the spindle in either direction

d) if door juts out at the bottom, the door needs to be tucked in closer to the roller support bracket. Try to get all slop erased AND pull the roller assembly towards the door so the horizontal roller is pulled against the door side of its track hidden under the door sill. The half-million mile Road Warrior required that I file the doorside radius of the roller support bracket all the way up alongside the 6mm screw so I could get the door flush with the b-pillar.
(bracket in the below photograph was hit with 320 grit sandpaper followed by a little 800 grit and clearcoat for an understated satin shine)

A smooth sliding door is a real treat. I can vouch that these mechanisms can work perfectly for a very long time with just periodic lubrication.
Colin

(so . . . what's the SECRET?? Here's the secret: with both upper and lower rollers aligned for a straight shot, I do not use any lubrication in the upper and lower tracks. Just a bit of garage door opener grease for the plastic glide in the hinge support. Keeps things cleaner. I maintain a good wax on both to keep the exposed metal from ever rusting. The real lubrication is in the roller-to-spindle interface. Wow! What a secret!)

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www.itinerant-air-cooled.com

[Randomwonderer]

It was the excellent detail that allowed me to fix my sliding door problem. I truly appreciate your assistance and wonderful documentation. Slider is now tight and serviceable which will allow us to try a drive longer than a few feet without losing the passengers!! Thanks for the interest to help us beginners!

[Tcash]

I second it.
Thank you Colin
Tcash

[mark d]

bookmarked, thks
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1972ish westfalia

"what good are tractors without violins ?" jose figueres

[curtp07]

Darn it, another item on my list...thank you great write up!
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Subaru

[KentABQ]

Great information and documentation! I'm looking forward to hearing a "whoosh click" instead of the current "screeeeeeech bang" along with the rust particles left under the length of the slider. Oh, the joys of taking custody of a 40-year old bus that has been sitting outside for too long.
She is now in a garage and living in a very dry climate, so I'm looking forward to addressing her various problems.
And now I know how to do it correctly, thanks to your posting. I especially appreciate the great camera angles.
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-Kent-
1976 Riviera, 1.8l FI chrome yellow VAN - "Chloe"

"I must say, how can you be in a bad mood driving this vehicle full of vibrant color.
Cars of today are so bland in comparison. It's like driving a celebration!" ---WildIdea

Bus ownership via emoticons:
---williamM

[SGKent]

as an addendum - as the bus travels it is constantly picking up dust, sand and debris - especially in climate like the SW or where sand and rock dust is used on the roads in winter. When the bus is washed, get a rag and some soap up into the area where the nylon slider rides. Hose that area out well once in awhile, then re-grease the rail a little. That will keep the door opening and closing well. The nylon will last longer too.

If the nylon wears to the rivet, the rivet will wear a notch into the rail. To repair that one must smooth the rail with a file and sandpaper, possibly building the surface back up with a small MIG welder if it is notched or worn badly. Replacement rails are available but they are welded on.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[chabanais]

Thank you this is the type of job I should do but have been putting off.

On a related topic, the latch that bolts into the door attaches with what size bolt? Does anyone know?
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"I spud therefore I yam."

[surfbus23]

This was exactly what I was looking for. Any tips on getting the bearings off the spindle? Mine seem to be pretty well stuck on there. I got the circlips off, but nothing is coming "right off".

Thanks,

K

[Tcash]

[surfbus23]

I'd been hitting it with some Kroil but not luck. After taking a break to work on some other stuff I decided I'd give it a gentle shot using the 3-prong gear puller. A rarely used tool, but with some care I was able to get snug under them and lift them off. All good enough to be reused, but pretty gunky after 45 years.