3rd gear grinding. Worn synchro?

Issues pertaining to the C30X, TGB series engine and driveline issues
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jlager
Posts: 29
Joined: Fri Oct 14, 2016 12:20 pm

3rd gear grinding. Worn synchro?

Post by jlager » Thu May 18, 2017 4:13 pm

I have an issue with 3rd gear grinding when up shifting and down shifting (down shifting much much worse but up shifting is bad too). If I double clutch, it helps some. When the truck is cold, it's pretty bad regardless of double clutching or not. When warm, 95% of the grinding noise goes away when up shifting and double clutching. Down shifting is still really bad when warm and double clutching.

Is this a worn synchro or something else? What are my options for fixing it?

Uli-RT
Germany
Posts: 57
Joined: Wed May 16, 2012 7:27 am
Location: Baden-Württemberg

Re: 3rd gear grinding. Worn synchro?

Post by Uli-RT » Fri May 19, 2017 11:31 am

...have you checked oil level ?
changed oil ?
If that does not help you have to change the synchronring.

For downshifting it will help reving it a little bit up while doublechlutching.
First you can try if its better resting a little bit longer in N if you change gears.

jlager
Posts: 29
Joined: Fri Oct 14, 2016 12:20 pm

Re: 3rd gear grinding. Worn synchro?

Post by jlager » Fri May 19, 2017 11:47 am

Uli-RT wrote:...have you checked oil level ?
changed oil ?
If that does not help you have to change the synchronring.

For downshifting it will help reving it a little bit up while doublechlutching.
First you can try if its better resting a little bit longer in N if you change gears.
Thank you for the reply.

Yes I have replaced the oil twice just to flush anything old out. It helped a little bit but not much.

For changing the synchroring, where could I get parts for this? I've tried looking up the zf s4-18 gearbox but there is almost nothing online.

I don't know much about gearboxes. Would a synchroring from something else work and would a mechanic be able to make another one work?

Uli-RT
Germany
Posts: 57
Joined: Wed May 16, 2012 7:27 am
Location: Baden-Württemberg

Re: 3rd gear grinding. Worn synchro?

Post by Uli-RT » Fri May 19, 2017 12:13 pm

may be this can help:
http://www.c303.de/c303-pdf/parts-list/ ... ogue15.pdf

The Pinzgauer does also have a ZF Gearbox. Perhaps you can find some parts there:
www.puch.at

Uli-RT
Germany
Posts: 57
Joined: Wed May 16, 2012 7:27 am
Location: Baden-Württemberg

Re: 3rd gear grinding. Worn synchro?

Post by Uli-RT » Fri May 19, 2017 12:16 pm

...more details for Puch:
http://www.puch.at/2751_Antriebswelle.aspx?LNG=de


Looking at the prices I would go for a good used gearbox.

jlager
Posts: 29
Joined: Fri Oct 14, 2016 12:20 pm

Re: 3rd gear grinding. Worn synchro?

Post by jlager » Fri May 19, 2017 6:31 pm

Uli-RT wrote:...more details for Puch:
http://www.puch.at/2751_Antriebswelle.aspx?LNG=de


Looking at the prices I would go for a good used gearbox.
Thanks for the info. Yikes! Yeah, I'm looking for a used one now...

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GadgetPhreak
United States of America
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Re: 3rd gear grinding. Worn synchro?

Post by GadgetPhreak » Fri May 19, 2017 10:30 pm

I picked up a remanufactured unit from Expedition Imports that I've been really happy with. Throw some Redline MT in it and you're good to go :)


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one2many
Australia
Posts: 128
Joined: Sun Dec 22, 2013 5:53 pm
Location: Melbourne Australia

Re: 3rd gear grinding. Worn synchro?

Post by one2many » Sun May 21, 2017 10:00 pm

I didn't realise EI sold parts for C30x series Volvos, they don't have a section for them on their website.

The pinzgauer ZF SF5-13 and Volvo ZF SF4-13 share some common parts between them and synchro rings will most likely be the same part... https://www.pinzgauer.com/showdetails.p ... 101225101/ ...$28.50 (USD).
The synchro engagement hubs could also be interchangeable as well as some of the bearings. The main shaft, lay shaft and gears will definitely not be interchangeable. (Gears will swap between all SF-13 series gearboxes but ratios will differ). Gear shifter setup is also different.

Gear oils with a rating GL-5 or higher will cause premature failure of synchro rings, I would also recommend the use of Redline MT90 gear oil in the gearbox and T-case.

On a final note when I was checking parts availability and cost for my pinzgauer gearbox I went directly to ZF and found that they were able to source parts for the SF5-13, however their prices were high so I didn't end up dealing with them.
1985 pinzgauer 712K factory 2.7lt civilian (RHD, 4 door K)
1979 Volvo tgb 1314a (under construction to om606 diesel/722.6 trans. Dual cab/tray)

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