Mercedes-Benz Forum banner

1 - 20 of 37 Posts

·
Registered
500E many W124 Wagon and R129 500s
Joined
·
384 Posts
Discussion Starter #1
hi 1994 e300 wagon 120,ooo miles

have been having the age old hard shifts,so suspected vacum or pressure accumulator
needing attention.
this was present in the hot weather we were having-then last week ( 1st oct) we had a really
cold morning ,when drove the car it was as if it had a brand new transmission,smooth shifts
changing smooth as silk...
till got warmed up,then it began to shift very hard again.

i am now ruling out the vacum & accumulator and i am thinking if used a heavier grade trans fluid
and replaced the filter in the trans ,this might cure the harsh shifts

the shifts when warm are the often reported ,sounds like the pro shaft slamming when
changing

am i correct in thinking heavier fluid may help ?working on the theory that when cold the oil is heavier
and when gets warm it is thinner ??

appreciate any thoughts on this before i end up tweaking the regulator back a turn (ish)

alann uk
 

·
Registered
'95 E300 DIESEL, '91 600SEL, '92 600SEL
Joined
·
16,899 Posts
The only proper spec fluid is Dexron IID or (Dexron III). Using anything else is asking for major trouble.

Start by draining the trans fluid (trans body + torque converter), install a new MB filter and pan gasket and refill. Then report back.

Do NOT powerflush the transmission under any circumstances.
 

·
Registered
500E many W124 Wagon and R129 500s
Joined
·
384 Posts
Discussion Starter #3
hello sbaert

will do exactly as advised,many thanks for your advice ,

if still no better when done that i will try adjusting vacuum modulator
i thought there may have been a heavier fluid.

will report back with outcome soon

alan
 

·
Registered
'95 E300 DIESEL, '91 600SEL, '92 600SEL
Joined
·
16,899 Posts
One more thing. Be sure to only use a top quality Dexron IID fluid, such as Fuchs Titan 3000

Also, what is the service history on your transmission? These cars require regular trans fluid and filter changes. Ideally every 25K miles, 30K miles max.
 

·
Registered
500E many W124 Wagon and R129 500s
Joined
·
384 Posts
Discussion Starter #5
will check invoices see when last done - i have recently bought the car so will need to look back
through invoices etc.looking at sump pan bolts etc ,nobody been into it for a long time

alan
 

·
Registered
'95 E300 DIESEL, '91 600SEL, '92 600SEL
Joined
·
16,899 Posts
...nobody been into it for a long time

alan
In that case, it is vital that you check the current fluid condition on the dipstick first. If it doesn't look cherry red, beware. And if the fluid appears dark, do NOT change the fluid at all. Otherwise, you risk the transmission failing almost immediately.
 

·
Registered
500E many W124 Wagon and R129 500s
Joined
·
384 Posts
Discussion Starter #7
again will follow your advice - i have arranged for it to go to a auto trans shop
for them to adjust the modulator and adjust the vaccum. he is an old school guy
who has a lot of experience on the old transmissions.will report back next week
when its been into his shop.

cheers al
 

·
W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
Joined
·
12,648 Posts
The transmission pressure modulator gets its vacuum from the intake manifold. There isn't a "vacuum" adjustment. The modulator has a pressure adjustment that controls how firm the shifts are. Have your mechanic check the rubber connectors at both ends of the vacuum line from intake to modulator.

Report back

Jayare

Sent from my XT1710-02 using Tapatalk
 

·
Registered
500E many W124 Wagon and R129 500s
Joined
·
384 Posts
Discussion Starter #9
The transmission pressure modulator gets its vacuum from the intake manifold. There isn't a "vacuum" adjustment. The modulator has a pressure adjustment that controls how firm the shifts are. Have your mechanic check the rubber connectors at both ends of the vacuum line from intake to modulator.

Report back

Jayare

Sent from my XT1710-02 using Tapatalk
hello jayare

appreciate the advice - i can do that myself -will look at that before having the a/t
guy alter the modulator

alan uk
 

·
W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
Joined
·
12,648 Posts
hello jayare

appreciate the advice - i can do that myself -will look at that before having the a/t
guy alter the modulator

alan uk
FYI - the pressure modulator is mounted to the left side of the transmission...Turning the adjuster (slightly) clockwise firms up shifts.

Sent from my XT1710-02 using Tapatalk
 

·
Registered
500E many W124 Wagon and R129 500s
Joined
·
384 Posts
Discussion Starter #11
thanks jayare will make sure i pass that info on to trans guy

alan uk
 

·
W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
Joined
·
12,648 Posts
If the trans guys doesn't know exactly where the pressure modulator is located, find another trans guy.

Sent from my XT1710-02 using Tapatalk
 

·
Registered
W124
Joined
·
4,740 Posts
A good Indy tech who worked for a Mercedes dealer back in the day would know these transmissions inside and out would be the guy to go to.

When thinking about fluid, also remember that the filter has to be designed for the fluid expected to pass through it. The transmission filter doesn't have a bypass so if it becomes a point of poor fluid flow, the impact downstream is slipping clutches and overall accelerated transmission wear.
 

·
Registered
500E many W124 Wagon and R129 500s
Joined
·
384 Posts
Discussion Starter #14
hello again -he is old school been around since the seventies ,i could adjust the modulator myself but would have needed his vaccum gear to test pressure - it should be a pint of beer type charge so best left to him !
he is the only one left now around these parts that only want to do a full trans rebuild and nothing else

alan
 

·
Registered
500E many W124 Wagon and R129 500s
Joined
·
384 Posts
Discussion Starter #15
thanks tuttebenne - at leaset the old 722 transmissions are fairly basic not like these modern ones that you need
a scientist to diagnose. i thought 7G was some sort of world leaders summit meeting !
 

·
Registered
W124
Joined
·
4,740 Posts
hello again -he is old school been around since the seventies ,i could adjust the modulator myself but would have needed his vaccum gear to test pressure - it should be a pint of beer type charge so best left to him !
he is the only one left now around these parts that only want to do a full trans rebuild and nothing else

alan
I don't want to think about a few short years from now when old school, talented, Indy mechanics retire.
 

·
Premium Member
'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
Joined
·
10,174 Posts
I don't want to think about a few short years from now when old school, talented, Indy mechanics retire.
It's already happened/happening. What's gonna happen is....there will be various centers across the country where only they will be able to perform the repair....like Sun Valley. AFAIK, Sun Valley is the only current place that will reman a TC other than buying one through a dealer.

And when that happens, they set the prices; you pay or you're on foot/bicycle. Almost like corporate farming, but not with as much evil intention.

Kevin
 

·
Registered
500E many W124 Wagon and R129 500s
Joined
·
384 Posts
Discussion Starter #18
hello again
(1994 w124 estate 300d auto )

After waiting 4 weeks now to get into the old school tranny shop - the old school a**hole keeps telling me he will ring me when gets a car off his ramp -he has not rang in 4 weeks ,I kept expecting a call ---Now I get the message he doesnt want to do it ! why not just say - ive wasted a flipping month

SO ......

i have been looking for a transmission modulator for my 722.4 auto box
coupled to my 300 diesel 1994 -the one thats already in the tranny, is a pink colour -it may have been red when fitted back in the past but is very pale red/pink

i have read all the posts- and now i am confused with all the upgrades available - especially the kent brockman videos
who says I should upgrade it - so should i be going for a black one or green one that gives better shifts ??

if anyone can advise the best one for my year/trans I would be very grateful
for the heads up before i buy a replacement to install myself (should have done that to start with )

many thanks

al england
 

·
Registered
'95 E300 DIESEL, '91 600SEL, '92 600SEL
Joined
·
16,899 Posts
For long term durability, stick with stock genuine MB components whenever possible.

It's the option with the fewest questions. Yes, you will be a bit more upfront but that premium price will be offset by durability.

Probably for the best you didn't go to that trans guy. Story sounded very fishy from the very beginning.
 
1 - 20 of 37 Posts
Top