I have a 1985 380SE (722.310 tranny) which won't go into fourth gear. The auto has been OK except now it looks like a new B2 piston is due (220000 kms and slipping in forward only). The fourth gear has never engaged and I am wondering if this might change when I install the new B2 piston and accompanying bush?? While doing this work I would like to try to do what I can do fix the fourth gear. Also I will check the modulator which so far holds vacuum. Any input on these subjects would be appreciated. Thanks. Ed

Are you sure you are not getting 4th gear? Our US 380SE's start in second unless manually held in "B" to start. We do not have First Gear Start unless we buy the kit. Unless your revs are really high you are in 4th.

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1986 Euro 500SEC "RUF" 9:1CR, "Rose"
1985 Euro 500SEC Cabriolet AMG Widebody
1982 Euro 500SEL "Blue"
2001 Texas Heeler (Aussie/Queensland X) "Sulphie",
2012 Queensland Red Heeler "Squeak"
Best dogs I've ever had.

Yes I'm sure. In Oz only the 500's started in 2nd. Mine goes 1-2-3-(no 4). At present I'm researching repairs because forward gears are not engaging properly. Car has done 220000kms (135000 miles). Once I remove the pan I'll know whether to go ahead and repair or remove the box. I understand that cleaning out the valve body and replacing a faulty modulator can revive fourth gear (I wonder if replacing the K2 spring will assist fourth also)) but first I need the B2 piston to operate so the car will move forward. All fun and games! Thanks.

The OZ 380's started in second gear also.

Series I 126's have a relatively low ratio diff and it appears that there are high revs at relatively low speeds.
Series II 126's - 300,s, 420's and 560's got a higher ratio diff which lowered the revs at higher speeds and gave consequently better fuel economy.

If you hold the gear change in the lowest position from rest you will use first gear. You will notice that is verrry low. It will give you a brisk take off before changing into second gear.

This should be referenced in your owners manual.

Australia never received the series I 126 500's. All are private or grey imports.

Thanks. Funny thing about the 4 speed transmission. When I bought the car 2nd hand it started in first and ran only to third. The owners manual says that the 380's start in first while the 500's start in second. Now I have just replaced the B2 piston (with sleeve and seal) as well as the K1 kit, it starts in second and runs to fourth. First is there, but only on kick-down. The thing now is that it sems to "clunk" a bit at low speed between 2-3 and with little to no accelerator pressure.

Mine does the clunk too!!! I thought I had it fixed when I corrected a flareing issue, which quickly re-materliazed unless the trans if FULLY warmed up!!

The more I drive the car, the more I'm convinced here is whats happening,

First is WAY SHORT, second you can feel it bump into and then it CLUNKS which I believe is third ,,,,, it revs 3200 rpm at 70mph

planning on doing motor and trans MOUNTS soon, I'm in the process of rebuilding shredded engine "shock mounts"

I'm going to go read your post about transmission fixed!!

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-SpecialDelivery
1985 300CD Silver/Blue H&R Suspension (Sold, still cryin over that)
1982 300SD Silver/Blue '85 OM617 (Sold)
1982 300D - Blue/Blue (Sold)

OK so I most likley am getting into 4th gear, but at very low RPM

I got my valve body torn down, cleaned and all new springs, it helped, car no longer flares from 2nd to 3rd, if it's starting in 2nd and shifting to 3rd, it's doing it pretty soon, then when it hits about 20-22 mph, it' CLUNKS into 4th

have adjusted vac and detent cable which produce different variations of this problem, I'm off to read read read

__________________
-SpecialDelivery
1985 300CD Silver/Blue H&R Suspension (Sold, still cryin over that)
1982 300SD Silver/Blue '85 OM617 (Sold)
1982 300D - Blue/Blue (Sold)