Register Login
FIAT Auto Specialist Team
Reply
 
Thread Tools
Old 30-05-2017   #796
Chichi and Qing Qing
 
pandamonius_maximus's Avatar
Join Date: Feb 2006
Location: Gloucestershire
Posts: 3,042
Thanks: 108
Trader Rating: 0
pandamonius_maximus has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

Well...

definitely feeling a bit out of my depth now.

The selector doesn't go on any other splines sadly, and even with it in the 2 position it will go on the same problem occurs.

I tried fitting the stiffer spring onto both the "1 & 2" and "5 & rev" shafts to see if it would help resist 2nd gear going in when selecting reverse but it still happens.

I am beginning to think that the gear stacks are matched /shimmed to the casing. So the gear positions relative to the selector position on the casing is wrong. So could just throw the 4x4 gear stacks back in and live with it. Or... use the Y10 casing instead of the 4x4 casing (assuming it bolts onto the FIRE 4x4 bell housing). But the workshop manual states gear casing is matched to engine mounting casing ... aka bell housing so this could cause other alignment issues...

Either way, the gearbox comes out for those so...

...think I might just make sure I never go from 2nd to reverse. It's not something that needs to be done even if it does seem to happen naturally when pulling up to a parking space! And I can take the selector cover off and manually pop it out of 2nd I guess! Can't be bothered to take gearbox out again! And when it happens it doesn't cause any damage...
pandamonius_maximus is offline Reply With Quote Quote 
Old 30-05-2017   #797
I choose you!
 
blu73's Avatar
Join Date: Nov 2004
Location: Pallet Town
Posts: 16,939
Thanks: 362
Trader Rating: 2
blu73 has donated!
Snowboard Slalom Champion, Skate Boarder Champion
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

well this certainly sounds like an annoying as hell issue but like you say, its one that can be lived with... I also would just leave it for the time being, you may have a moment in the future but no real point completely dismantling now without an actual plan that will fix it as i see it.
Likes pandamonius_maximus liked this post
__________________
Charmander - Panda Mania 1242 mpi 8v - thread
Unnamed - Panda 100HP - thread
Oberyn - Suzuki Ignis Sport - thread
Some previous cars: Alfa 159, Bravo HGT, Cinq 16v, Sei Turbo, Punto GT
blu73 is offline Reply With Quote Quote 
Old 30-05-2017   #798
Chichi and Qing Qing
 
pandamonius_maximus's Avatar
Join Date: Feb 2006
Location: Gloucestershire
Posts: 3,042
Thanks: 108
Trader Rating: 0
pandamonius_maximus has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

Yeah, is what I am feeling now. Think I have exhausted all the possible silly mistakes. I think it must now be something which is normally set at the factory.

Using the spare 4x4 gears and Y10 casing have had a look at the reasons behind this issue.

Here are all the gears in the neutral position:


This is with reverse engaged:


as reverse engages it must mesh the idler gear (the gear at the bottom of the following image on it's own shaft):


which is why the edges are rounded to help guide them in. However if they don't mesh properly then they will push this gear up instead and this will force 2nd gear to engage as well. This is the 2nd gear selected position:



So I believe the idler gear is not the right size and perhaps this is picked from various sizes in the factory...perhaps I should have used the 4x4 one which came with this casing, rather than the Y10 one...

Anyway, think I am living with this as a risk for now. Unless new information comes to light
pandamonius_maximus is offline Reply With Quote Quote 
Old 31-05-2017   #799
Chichi and Qing Qing
 
pandamonius_maximus's Avatar
Join Date: Feb 2006
Location: Gloucestershire
Posts: 3,042
Thanks: 108
Trader Rating: 0
pandamonius_maximus has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

It'll be like this....totes!...

pandamonius_maximus is offline Reply With Quote Quote 
Old 19-06-2017   #800
Chichi and Qing Qing
 
pandamonius_maximus's Avatar
Join Date: Feb 2006
Location: Gloucestershire
Posts: 3,042
Thanks: 108
Trader Rating: 0
pandamonius_maximus has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

OK so been a little while since reported. I took gearbox out again to try to get to the bottom of this gear selection issue. But it's looking like something I will have to live with for now.

This time I tried fitting all the stuff from the 4x4 Panda gearbox except the diff, and the gear stack shaft which has the correct final drive output gear on it. All the gears and synchros are now from the Panda 4x4, including the reverse gear. It still knocks into 2nd when going into reverse though, so I have now made a small inspection hole right above the 1st and 2nd gear selector shaft...so I can easily knock it back out if it does it again. But the trick of making sure I never go from 2nd gear to reverse seems to hold for removing the issue anyway.

On a more positive note...after a roady test yesterday I decided to treat the car to something I wanted to do for a while...yellow headlights





Ready to receive a prop shaft... which I need to get on top of really as have let comms slide a bit with the manufacturer! It'll be a brand new, and strengthened prop hopefully.
pandamonius_maximus is offline Reply With Quote Quote 
Old 19-06-2017   #801
769cc Mayhem!
 
Didge3's Avatar
Join Date: May 2012
Location: Quite south.
Posts: 2,955
Thanks: 49
Trader Rating: 0
Didge3 has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

I went the yellow bulb route when I decided I needed yellow lights



They looked cool when lit (IMO) but awful in practise, it was like driving with a couple of candles in jam jars
__________________
FIAT-LESS
Didge3 is offline Reply With Quote Quote 
Old 19-06-2017   #802
Chichi and Qing Qing
 
pandamonius_maximus's Avatar
Join Date: Feb 2006
Location: Gloucestershire
Posts: 3,042
Thanks: 108
Trader Rating: 0
pandamonius_maximus has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

Quote Originally Posted by Didge3 View Post
I went the yellow bulb route when I decided I needed yellow lights

They looked cool when lit (IMO) but awful in practise, it was like driving with a couple of candles in jam jars
Yeah I actually got the desire from having a set of yellow bulbs I got from the donor Y10 turbo lights. Loved the look when lit, and these weren't too dull either but they blew and I couldn't find the same ones again. Not sure how good this will be at night, but the Marbella headlight design is much better for lighting up the road anyway. Will try to give it a test drive soon and a video as well...
pandamonius_maximus is offline Reply With Quote Quote 
Old 20-06-2017   #803
769cc Mayhem!
 
Didge3's Avatar
Join Date: May 2012
Location: Quite south.
Posts: 2,955
Thanks: 49
Trader Rating: 0
Didge3 has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

Quote Originally Posted by pandamonius_maximus View Post
Yeah I actually got the desire from having a set of yellow bulbs I got from the donor Y10 turbo lights. Loved the look when lit, and these weren't too dull either but they blew and I couldn't find the same ones again. Not sure how good this will be at night, but the Marbella headlight design is much better for lighting up the road anyway. Will try to give it a test drive soon and a video as well...
I do think they look cool on Pandas and Marbellas alike of course...
Had an MOT tester tell me that yellow weren't allowed. He'd already swapped the bulbs for regular white ones and thrown my yellows away already, got very grumpy with him since yellow is legal, so be wary of that.
__________________
FIAT-LESS

Last edited by Didge3; 20-06-2017 at 02:01.
Didge3 is offline Reply With Quote Quote 
Old 29-06-2017   #804
Join Date: Sep 2004
Location: Dundee
Posts: 1,648
Thanks: 144
Trader Rating: 1
Giacosa has donated!
Lunar Lander 2 Champion
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

Loving the yellow lights, looks more demented than before. I wish i could help with gearbox conundrums but i know far too little about them.
Likes pandamonius_maximus, onemanmade liked this post
__________________
FIAT Forum Useful Links:
Donate to FF | Buy FF Merchandise | Classifieds | FF Insurance | How-to Guides

Giacosa is offline Reply With Quote Quote 
Old 09-07-2017   #805
Chichi and Qing Qing
 
pandamonius_maximus's Avatar
Join Date: Feb 2006
Location: Gloucestershire
Posts: 3,042
Thanks: 108
Trader Rating: 0
pandamonius_maximus has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

Prop-shaft update!

The car has been checked over by the propshaft builders and I have some mounting suggestions which are going to keep my busy for a little bit.



So there are basically too many angles going on, 9° down from the gearbox output, ~10° rear diff angle down, and prop shaft angles to centre support bearings are too great too. Summary of the issue and solution courtesy of powerpoint:



So it's back to 2009 again for engine mountings



But I have now got the output from the gearbox down to 5° and this is probably the best that can be done. So need to mount the centre bearings so the front prop shaft angle is 0° mid section will be at 0° and rear prop shaft section I am hoping will be around 2° up to the diff. So will still be a bit of a C shape going on but tbh no worse than a standard 4x4 panda...so hoping this is enough to go forward with the custom prop shaft!
Likes FDNY21, andyholli liked this post
pandamonius_maximus is offline Reply With Quote Quote 
Old 09-07-2017   #806
Join Date: Apr 2013
Location: Liverpool
Posts: 973
Thanks: 51
Trader Rating: 0
andyholli has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

Great progress (I'm sure I can smell the beginning of the finish line) but can you explain the physics of this problem to me - I thought a joint was a joint, why do these minor angles matter so much please?

It's not keeping me awake but it is bothering me that I don't understand at all, absolutely not a clue..

Cheers Si.
andyholli is offline Reply With Quote Quote 
Old 09-07-2017   #807
Chichi and Qing Qing
 
pandamonius_maximus's Avatar
Join Date: Feb 2006
Location: Gloucestershire
Posts: 3,042
Thanks: 108
Trader Rating: 0
pandamonius_maximus has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

Quote Originally Posted by andyholli View Post
Great progress (I'm sure I can smell the beginning of the finish line) but can you explain the physics of this problem to me - I thought a joint was a joint, why do these minor angles matter so much please?

It's not keeping me awake but it is bothering me that I don't understand at all, absolutely not a clue..

Cheers Si.
I think it is a frequency of vibration issue. The straighter it is the higher shaft rpm it can be balanced to. The more bends in it, the more possible frequencies of vibration and the harder to balance / lower max allowable shaft rpm.

I'm told their calcs have said it can only spin at 900rpm if using it as it was...or 1500rpm if using a straighter path...so top speed of 33mph or 55mph! But I have now improved the output shaft angle to better than a normal Panda 4x4, and will only have kink on the rear section of the shaft now I hope...I'm out of ideas if they don't like that as the standard Panda 4x4 actually does this dangerous C shape they don't like (i.e. the front shaft has an angle of ~2° down, and the back shaft has an angle of ~2° up with. The angle of the gearbox output is 9°down on standard panda 4x4 too.

I reckon we're just playing it safe tbh...which can't hurt I guess! Probably be good up to 200mph when we're done
pandamonius_maximus is offline Reply With Quote Quote 
Old 10-07-2017   #808
Join Date: Nov 2005
Posts: 2,832
Thanks: 230
Trader Rating: 0
panda1408 has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

With my limited knowledge on the subject I think I am correct in thinking as the front section of the shaft uses CV joints the angle of the flanges is not such as issue. The CV joints will maintain a constant velocity regardless of whether the flange angle is equal, hence their name. CV joints will have a max working angle however so that needs to be taken into account

With universal joints as used on the rear section the flange angles need to be equal otherwise the shaft velocity will vary as it spins, causing vibration and such issues. This is basically the reason CV joints are widely used.
Likes pandamonius_maximus liked this post
__________________
1988 Panda 4x4 Sisley
1982 Panda 45
panda1408 is offline Reply With Quote Quote 
Old 10-07-2017   #809
Join Date: Apr 2013
Location: Liverpool
Posts: 973
Thanks: 51
Trader Rating: 0
andyholli has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

CV joints go through much greater angles than these (but at generally lower rpm) on the drive shafts. If the single rear UJ is the only potential cause of vibration (once the shaft is balanced) then twisting the diff nose up to straighten it out - per Si's diagram should be a fix..
- Would tilting it that much significantly move any suspension pick ups? - I don't think so, just damper mounts back a bit.

Also - don't forget we've tested the standard 4x4 prop set up beyond 100mph without a problem.[winky face]
Likes pandamonius_maximus liked this post
andyholli is offline Reply With Quote Quote 
Old 10-07-2017   #810
Chichi and Qing Qing
 
pandamonius_maximus's Avatar
Join Date: Feb 2006
Location: Gloucestershire
Posts: 3,042
Thanks: 108
Trader Rating: 0
pandamonius_maximus has donated!
United Kingdom 
Re: SEAT Marbella (Mk1 Panda replica).

To be honest I am putting my faith in this prop shaft expert as I didn't want to cause massive issues / waste lots of money destroying a propshaft...but it doesn't completely make sense to me either. We know the Panda has fairly large angles and gets away with it...maybe this is a simple power thing...the more power you put through it the more aggressive the vibrations...

Anyway I have successfully reduced the output of the gearbox down to 3.5° down (using genuine mk1 panda gearbox mounts now as they have a taller bracket); with the centre bearings bolted directly to the bottom of the car I should have a roughly horizontal front shaft and mid shaft. The only bend will be up to the rear...can't see why that wouldn't be ok...please let it be ok!!

Side benefit to this lowering of the engine:

- I now have space above the alternator so I can properly tension the belt!

- Centre of gravity is lower so of course I will go quicker...it's a given!

Downsides of lowering engine:

Water pipes and induction pipes are going to need re-positioning as are stretched and squished in their new position...with a small water leak resulting...

Carburettor is stuffed up against the radiator which should really help with the carburettor overheating issue...

Exhaust mounting needs re-working...it's got a bit close to the floor unsurprisingly!

I will do a proper drawing and email to the prop shaft chaps...then will probably tell them to build one for me despite their concerns...or find out they are totally happy with what I have done and put my feet up and not think about it again.

Dark now so will grab photos tomorrow hopefully
Likes Didge3 liked this post
pandamonius_maximus is offline Reply With Quote Quote 
Reply
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump
Similar Threads
Thread Thread Starter Forum Replies Last Post
(T) Seat Marbella/mk1 panda suspension (bike engined) Dalemaltby Panda (Classic) 60 08-08-2014 10:37
Panda (Classic) Seat Marbella/mk1 panda suspension (bike engined) Dalemaltby Newbie Central 0 06-10-2013 06:45