Calling the Experts : Flange angles on Syncro's.

[Jon_slider]

[bsrad]

[flomulgator]

I'm working through improving my alignment. Reading Shooftie's blog helped me understand things even better, thanks for that. I need to raise my nosecone just a tad. I read this part:

[flomulgator]

So I unbolted the front differential mount and jacked it up, slowly letting it back down until the measurement from centerline on the trans to the ground was the same as the front* (actually since my laser was making concentric circles this involved a healthy dose of geometry). I then placed enough fender washers under the rubber mount to pull the jack away and re-bolt in the slightly elevated position. Took it for a test drive and found the vibrations above 60 to be reduced! They are now barely perceptible, it takes a well-tuned ass to detect them. FWIW my driveline does not have an angle to the protection bars (0° droop).

* I am aware that this method is inherently flawed, as distance from the ground does not equate to angle of the object. However, given that both nosecones are fairly close to engineered hinge points (chassis mounts) it seems a decent kludge that avoids the challenge of trying to measure flange angle at the U-joints themselves. If anyone has a simple method of measuring flange angles, please post it!
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[Jon_slider]

I measure flange angles w iphone app Clinometer, without removing propshaft. If you jack up rear of van to make propshaft level, you can skip the math and just use the angles reported

I measure vibrations with iphone app iSeismometer, with phone in a secured Proclip mount

To be sure vibes are not from other factors, remive oropshaft and get a baseline from iSeismometer
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My Soapboxes: Inflation; Handling; Gearing; Decoupling; Swepco

[flomulgator]

How do you get a good alignment between your phone and the flanges?
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She's built like a steakhouse, but she handles like a bistro!

[Jon_slider]

The edge of the phone fits against the part of the diff flanges that are wider than the propshaft flange.
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My Soapboxes: Inflation; Handling; Gearing; Decoupling; Swepco

[flomulgator]

I think I'm envisioning this wrong; are you saying that you rest the phone vertically against the back of the diff / trans flange to measure the angle from vertical?
Because otherwise I'm imaging the phone placed horizontally against just the flange lip and that seems prone to significant imprecision.
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She's built like a steakhouse, but she handles like a bistro!

[Jon_slider]

Yes, long edge of phone vertical on the small amount of flange that protudes. Theres enough to get a small flat surface to press the edge of the phone to, or remove propshaft for larger flat

Front and back of Phone face sides of van, left and right edges of phone face front and rear

Cant find a pic for you
Hope you understand
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My Soapboxes: Inflation; Handling; Gearing; Decoupling; Swepco

[flomulgator]

No need, that makes sense now. A novel approach!
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She's built like a steakhouse, but she handles like a bistro!

[nilza]

Hi from Australia!

I've been chasing a slight vibration for about a year now. That is finally now resolved, so I thought I might share my experience.

I replaced all the mounts with genuine, managed to find genuine specification unis from hardy spicer, managed to find a genuine donut out of germany and had a machine shop cut open the shaft, remanufacter the center bearings and regrind and chrome the pilot shaft inside. Everything has been laser aligned and flange angles are within 0.2 degrees

But I still had a slight rising vibration. I decided to do a bit of learning about balancing and the machines they use.

Long story short, the standard for balancing automotive propshafts is ISO G16, the Syncro shaft is balanced to higher standard out of the factory. Ask your shop to balance to G6.3.

Worked for me, smooth and buttery 4WD for now.
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still floating around the web somewhere

[Jon_slider]

[MsTaboo]

Another thing to keep in mind (maybe it was listed earlier) is the alignment of the transaxle to the front diff. They need to be inline with each other.
I used a regular construction laser to check this based on the case halves.

Also, (from watching that video Jael posted) all the up/down orientations while checking the angles are based on the the front of the vehicle.
So the drawing of the Syncro drivetrain on page 2 would be:
Front diff - down
Driveshaft - down
Transaxle - up

Have I got that right?
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'90 Syncro Westy 3 knob w/Zetec

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[vanagonjr]

[Steve Arndt]

On the topic of the drive shaft I have a question about mine. If I rock it back and forth by hand it makes a tink clink kind of sound inside. If I overly lug the engine I can also hear it. Is this the bushing inside being worn? It hasn't gotten worse over the last 15 years and doesn't vibrate. I'm curious.

Thanks
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Steve
Steve's 87 Syncro project

[Jon_slider]

[handjammer]

[bsrad]

[peterT3syncro]

Digging up an old thread I know, but looking for some ideas please.
I am trying to setup the driveshaft between the transaxle and front differential
My 1990 syncro equipped with a Subaru 2.2.
The last few years the vehicle has been in "dry- dock" have a full restoration.
I started on the driveshaft last week.
The original shaft I removed when I first parked the vehicle.
In the meantime I had opportunity to purchase a spare replacement shaft which is much like the GoWesty plain shaft - no rubber doughnut.
Having read various article about phasing, etc, I checked the flange angles at both the transaxle output and the front differential.
I had previously up graded the transaxle front mounts and front diff mounts with units from Chris at T3 technique.

Measuring angles I used my smart phone and the Inclinometer app.

With the vehicle setup level - chassis level with a spirit level, the transaxle flange had a reading of 0 degrees (vertical) - or output shaft (pinion) Horizontal or parallel with chassis rail.

The front differential had a down reading of 7 degrees.

Now, if you apply the logic in the following clip these angles are wrong.
https://www.youtube.com/watch?v=Idk3BVDVHq4

So, do I lessen the angle on the front diff and tip the transaxle nose down?

I don't see much adjustment at the engine mount? Possibly a SmallCar mount -(previous owner)

To raise the flange on the front differential - a certain amount can be raised but limited by the gear-shift conduit tube which is above the differential

I can see a way to raise the rear of the front diff which involves removing the hanger bar ( and flipping it over and positioning it under the diff, and extend the mount brackets back to the top of the diff hanging bolts.
The front of the diff is limited in adjustment due to the CV output shafts which are some 15mm above the chassis rails.

Anybody ?
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Peter

Type 3 Syncro Kombi, EJ22 Subaru

[tencentlife]

It doesn't matter what the flange angles are relative to the chassis or the ground, that's silly, the u-joints only see the net angle between the flanges, and the idea it has to be right at 8º is equally absurd. There just needs to be a small angle between the flanges so the u-joints lope. You have 7º, run it.

Take apart and lube the internal shaft/bushings, that's where most vibration and noise (the famous pinging) comes from.

Harder transaxle and front diff mounts can't create vibration but will accentuate any vibes there are. I can see using them for suspension elements for some applications but not for engine and trans mounts, there's no palpable benefit to stiffer mountings there.
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