Transmission not shifting up from 2nd gear

1965 - 1972: 250S, 250SE, 300SEb, 280S, 280SE, 280SEL, 280SE 3.5, 280SEL 3.5, 280SE 4.5, 280SEL 4.5, 300SEL, 300SEL 6.3, 300SEL 3.5, 300SEL 4.5
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mercmark
A Class
Posts: 10
Joined: Sat 27 Oct, 2012 8:46 am
Model you own: w108
Region: Victoria
Location: Geelong

Transmission not shifting up from 2nd gear

Post by mercmark » Sun 21 Oct, 2018 9:08 am

Hi all, after a bit of advice as I’m not mechanically minded at all. I was excited yesterday to pick up my 1971 3.5 from a workshop who was engaged by my ‘regular workshop’ to get the car running after replacing heads. After sitting for some 6 years and 7 months the transmission is now not shifting above second gear (was working fine previously). The workshop I picked it up from suspects the governor is jammed or it is a shift valve fault. I’ve booked it into a transmission shop down here in Geelong but I just wanted to get a sense from members if they’d come across this and is it likely to be a big job. Many thanks, Mark
1971 280SE 3.5
1971 280SEL 3.5
1991 190E 2.3
Live in Geelong but still call Tasmania home

CraigB
OZBENZ Admin
Posts: 5075
Joined: Thu 23 Jun, 2005 1:18 pm
Model you own: I own multiple different models
Location: Hawthorndene (Adelaide)

Re: Transmission not shifting up from 2nd gear

Post by CraigB » Sun 21 Oct, 2018 4:10 pm

So being a 4 speed trans (that starts off in second unless you hold it back with selector), are you saying it starts off in that gear and never changes higher to 3rd and 4th? Or just it won't change into top gear? I'm wondering about the modulator and did they put the vacuum line back on the manifold at the rear. Somewhere on here I reckon John Green said about tests to do. I think if you completely disconnect the bowden cable (that one from the accelerator linkage down to the trans) and see how it behaves. If they do that up too tight or put it back wrong that will hold it back in gears and stop it changing up. Before taking it in I would give those two things a go - check vac line good and attached from RHR of manifold next to head and also down onto the trans modulator - if you have a vac guage you can also see if the modulator holds vacuum. Then disconnect that cable and see what it does or try loosening it. I think if it is too loose it will just not kick down, but your problem is it not changing up and will give you an idea what's going on. Also could be worth changing fluid and also heard of success from people using that Lucas trans conditioner. All worth a try I reckon given it worked and then with heads changed and sitting around it didn't.
Craig Baulderstone
Lurch
280s's
280SE3.5
280SL
350SL
500SEC's
560SEL's

mercmark
A Class
Posts: 10
Joined: Sat 27 Oct, 2012 8:46 am
Model you own: w108
Region: Victoria
Location: Geelong

Re: Transmission not shifting up from 2nd gear

Post by mercmark » Sun 21 Oct, 2018 4:42 pm

Thanks Craig, I envy you guys who have this type of knowledge. The transmission changes up once so I presume from what you’ve mentioned that it changes from 2nd to 3rd then, but not beyond that. Looks like I will need to take it in to the shop as I don’t really know what I’m looking at when you describe this stuff - I’ll show the transmission guys what you have suggested.

I really must get some basic mechanical knowledge and/or start going to some MB Vic Club Meets so I start learning this stuff along the way.

Thanks again Craig. Cheers, Mark
1971 280SE 3.5
1971 280SEL 3.5
1991 190E 2.3
Live in Geelong but still call Tasmania home

CraigB
OZBENZ Admin
Posts: 5075
Joined: Thu 23 Jun, 2005 1:18 pm
Model you own: I own multiple different models
Location: Hawthorndene (Adelaide)

Re: Transmission not shifting up from 2nd gear

Post by CraigB » Sun 21 Oct, 2018 5:27 pm

Is your regular shop a Mercedes specialist? It doesn't sound to me like the 'other' workshop is worth going back to based on what said. Given the work done and that they would have to take the manifold off and refit, it they tightened your cable too much that is exactly what it would do and is a two minute job to loosen off. I know because i was trying to get mine to kick down quicker, and it did, but I went too far and wouldn't change up - bit looser and all good. I can't be sure what it is but just thinking out loud, its a shame if you are faced with a bill from a trans place if the other haven't got it right. And trans bills can be huge so I hope that place is good with your car. I see recommendations on here for good Vic specialists. I'm not jumping to conclusions as to how good these guys are but it comes up from time to time when places don't understand Benzes and make costly guesses - but your guys could be great and it all happen.
Craig Baulderstone
Lurch
280s's
280SE3.5
280SL
350SL
500SEC's
560SEL's

mercmark
A Class
Posts: 10
Joined: Sat 27 Oct, 2012 8:46 am
Model you own: w108
Region: Victoria
Location: Geelong

Re: Transmission not shifting up from 2nd gear

Post by mercmark » Sun 21 Oct, 2018 6:17 pm

It was a bit of a tricky one Craig. The regular workshop I went to get the head’s done had the car a very, very long time and they couldn’t get the car going again after they put everything back together so they contracted out to a Mercedes specialist who got it running and then advised me of this problem. I’ll ring the specialist tomorrow and mention what you’ve said as that all makes sense.

Can any other members tell me the specialists they use in Geelong?

Many thanks taking the time to respond again Craig.

Cheers, Mark
1971 280SE 3.5
1971 280SEL 3.5
1991 190E 2.3
Live in Geelong but still call Tasmania home

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