Rear end jumps

Buguyed · Posted: Wed Apr 23, 2014 10:52 am Post subject: Rear end jumps

Hello All,

When travelling at speeds over 45mph the car will jump to the side when I hit a pothole or bump in the road. This, as you can imagine, can be pretty scary. My car was down two outer splines in the rear. I recently raised it up one and the problem is still there, just not as bad. I also put on new shocks when I raised it. I'm running 5.5" smoothies with 165/80/r15s.

I took off the wheel last night to inspect everything. All the bolts are tight and the hub is nice and tight. I then discovered a possible missing bolt. Just to the left of the shock tower, it looks like a bolt goes through there.

1.Is this something I can just bolt together with a bolt from the hardware store?
2. Does a bushing go in there too?
3. Is there a specific name for this bushing, if it exists?
4. Can this be made myself?

Thanks everyone!
Nick

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fla2smoker · Posted: Wed Apr 23, 2014 11:22 am Post subject:

Not sure on the bolt if you can pick it up at a hardware store but you will need the rear shock tower bushing to go in between the body and the shock tower. Most places have them available.

http://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=111899119B
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Buguyed · Posted: Wed Apr 23, 2014 12:13 pm Post subject:

Do you know how thick it needs to be? Seems like something I can make at home with some rubber. I don't currently need anything from WW so i'm not sure i want to spend $10 on two small pieces of rubber with holes in them(shipping).

AND, more importantly, might this be the origin of my handling woes?
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1961 Type 1 Ragtop Gulf Blue

60ragtop · Posted: Wed Apr 23, 2014 12:30 pm Post subject:

my parts book shows either 17 mm or 10 mm available. measure it?
How is the other side?
Bolt you can get at hardware store, 10 mm
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Nevada Notch · Posted: Wed Apr 23, 2014 12:38 pm Post subject:

Also check your rear wheel alignment, it may be a toe in our out condition.
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Buguyed · Posted: Wed Apr 23, 2014 12:57 pm Post subject:

Both sides are the same, missing Shocked

I think a 17mm would be more fitting based on the gap. I'll stop by Napa or somewhere on the way home tonight and get some materials and a new 10mm Bolt to get this buttoned up.

Also, I had the rear aligned when I raised it up a spline and put new shocks on. It's all been part of my project to make my car handle safely.

I also recently traded my 5" no-shock tower front beam for a 2" narrowed beam with shock towers and drop spindles. Also did new bushings in front and new steering box. New front sway bar and camber compensator in the future..
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1961 Type 1 Ragtop Gulf Blue

vamram · Posted: Wed Apr 23, 2014 1:04 pm Post subject:

I bet that the missing parts affect the feel and handling when you hit bumps big time. This isn't a very technical assessment by me, I know, but I made the mistake a couple of years ago of buying a Bug w/out enough knowledge at first and had a similar situation.

The bolt and pad on both shock towers weren't missing like on yours, but the pads were worn to shreds - basically didn't exist - and the bolts were loose. The impact on the body was nasty when I encountered any kind of bump.

And it turned out that the PO also had left out the pads that go in front, between the body and the front axle beam, leaving a space btn the body front and the frame, and also only installed 9 of the 18 body-to-pan bolts!! The car was basically barely on the pan, and it bounced just like you described yours until I replaced every worn or missing part. I still get pissed about that to this day if i think about it much. Evil or Very Mad

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Buguyed · Posted: Wed Apr 23, 2014 1:43 pm Post subject:

vamram · Posted: Wed Apr 23, 2014 2:34 pm Post subject:

BTW - I bought all of the parts I needed from Wolfsburg West. The rear and front pads, body-to-pan bolts and shims. I don't know if they sell the bolts for the shock towers, I didn't need those.

http://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=111899165

U can see all of the pads on this link:

http://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=111899119B
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Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
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Save the Supers!!

drscope · Posted: Thu Apr 24, 2014 9:24 am Post subject:

The missing bolts are NOT the cause of your bad handling. They may cause loud clunks from the rear when you go over bumps but the handling issue has nothing to do with those.

Your handling issue has everything to do with the car being lowered and not having the rear wheels aligned properly.

The only way for the wheel to steer itself properly is for it to be standing straight up and down and pointed straight ahead.
When you lower the car the nature of the swing axle is that you introduce negative camber into the geometry. This means the wheel is leaning in at the top.

That negative camber in itself tries to steer the wheel towards the center of the car as you are trying to drive straight,

Then when you lower a swing axle, you also get Toe In as a result of the spring plate being angled up and pulling the axle forward.

Toe In will also try to steer the wheel towards the center of the car as you are trying to drive straight.

So on a perfectly smooth road with no bumps, while you are trying to drive straight, the two rear tires are scrubbing and fighting each other to see which one is going to have the most grip on the pavement.

This is the cause of excessive tire wear on the inner edge.

Now, when you throw in a bump, one rear wheel (or both) are going to lift off the pavement just for an instant. When that happens the one tire that stays on the pavement now has all the grip and it tries to take over steering the car. So it steers the rear of the car towards the center of the car.

So if the LEFT rear wheel is the one that lifts up, the right rear wheel takes over and tries to steer the rear of the car to the left. If the RIGHT rear wheel is the one that lifts off the pavement, then the left rear wheel takes over and tries to steer the rear of the car to the right.

Its actually pretty simple. And as the rear wheels fight to see which one is going to be in control, the car can actually be going down the road like a dog wagging it’s tail.

In severely lowered cars, extended spring plates are one band aide fix to help correct some of the Toe In, but the negative camber will continue to be a factor as long as the wheel is leaning over.

The only way to get rid of the negative camber on a lowered swing axle car is to raise up the transmission.

Basically you need to decide what is more important to you. Good handling and a nice safe feeling ride, or cool looks because the car is sitting low.
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vamram · Posted: Thu Apr 24, 2014 9:35 am Post subject:

Hmm...well, replacing all of the missing parts did seem to help. Certainly kept the body squarely on the frame!

I did add a heavy duty front-end sway bar since it didn't have one when I bought it. That made a huge difference in how it rode.

Not trying to hijack the OP's thread, but how do you align the rear on a stock-height swing axle?
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

Buguyed · Posted: Thu Apr 24, 2014 9:43 am Post subject:

drscope, thanks. The toe seems to be my issue here. That makes sense to me. I have driven other lowered swing axles and not experienced this which is what is confusing me.

Is there anyway to adjust the toe on the rear wheels while keeping my minimally lowered stature?

As for the camber, it is pretty much non-existent at rest/cruising. I can see hitting a bump, the torsion bars and shock would compress and create a negative camber (in effect, lowering). At that point the toe could be going in/out causing the issue.

Second question, would some 205/65/R15 wheels on the rear alleviate some of my issues? I would like to drive my car with something less than white-knuckles...

EDIT: I'm going to pour through this gem of a link I've discovered:
http://www.thesamba.com/vw/forum/viewtopic.php?t=400664
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1961 Type 1 Ragtop Gulf Blue

drscope · Posted: Fri Apr 25, 2014 11:13 am Post subject:

The 3 holes in the spring plate where the axle mounts to the spring plate are elongated holes. You set toe by moving the axle forward or back in those holes.

Need toe in, you slide it forward, back for toe out.

Sometimes you need to file the holes out even longer and if that isn't enough, thats where extended spring plates come in.
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Buguyed · Posted: Fri Apr 25, 2014 1:07 pm Post subject:

drscope · Posted: Fri Apr 25, 2014 5:36 pm Post subject:

Tire to tire - right side to left side. Same for setting front wheel alignment, just do that on the rear.
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Aussiebug · Posted: Fri Apr 25, 2014 6:41 pm Post subject:

And the rear needs toe OUT, not toe in. About 1/2 degree, or about 4mm difference in the measurement between the tires fore and aft of the axle - bigger measurement in front of the axle.
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Aynthm · Posted: Fri Apr 25, 2014 9:02 pm Post subject:

Tire pressure too high. Try 27 for the rears and 17 for the front. That'll fix the hopping around. Proper air pressure will glue the tires to the road surface.

Teeroy · Posted: Fri Apr 25, 2014 10:52 pm Post subject: Rear end jumps

Worn spring plate bushings ca cause/agravate your symptoms
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drscope · Posted: Sat Apr 26, 2014 6:57 am Post subject:

Soft tire pressures don’t really glue the tires to the road surface, they just sort of mask the problem by flexing and absorbing some of the movement between the ground, tire and wheel. It just feels better at the seat of your pants.

Worn spring plate bushings can cause/aggravate your symptoms. Thats true but there is also another side of the coin. Your symptoms (rear wheels out of alignment) can cause worn spring plate bushings!

Get the alignment right and all the rest will fell a lot better.
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Mother Nature is a Mean Evil Bitch!

Buguyed · Posted: Tue May 13, 2014 9:48 pm Post subject:

Ok update..

Finally got to tinkering tonight.
1. Measuring the best I could with my wife's help, the front of the rear wheel is 1/2" more narrow than the back is. This pretty much explains my issue I think.

2. I'm having a hard time connecting the body mount to the shock tower. The hole needs to slide about 1/2" forward to line up. Frustrating. Going to take things more apart this weekend to see if I can get it lined up. Maybe open up the holes on the spring plate a touch to fix my toe-in.
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1961 Type 1 Ragtop Gulf Blue


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