News:

Please add your location to your profile. It will help others to help you!

Main Menu

450SEL with weird rattle/clanking from the transmission area

Started by Zaxxon, 08 March 2016, 10:11 PM

pmark3100

I would take a look at the bolts that hold the flex plate and torque converter together. If one has gotten loose, it will sound like that. It may be as simple as a bit of loc-tite and put it back together. Let it go too long and it can wallow out the bolt receiver and you'll have to reweld than flush the converter. You might also have a washer that fell down in there.

I worked on a Plymouth Trailduster once that had a similar sound. Before I got very far into it, the owner sold it to me cheap as he didn't want to fool with it. That one had a knock that happened each time the engine rotated one time. The previous owner was positive it was a rod knocking. Removing the bottom cover and rotating the engine by hand to inspect the flex plate showed a bolt loose. It had been loose so long I pulled the bolt out and drove it like that for a while. Eventually, I replaced the engine with one that was proper for the truck and had a torque converter rebuilding place weld and retap the spot for the bolt to bolt into.

Your sound seems like something simple once you find it.

Zaxxon

Hi pmark3100 and daantjie,

Yes, that's a good thought and something I was kind of thinking about too. One of those bolts backed out somewhat will definitely make a racket like that. I have to see if I can snake my camera in there while trying to turn the converter with a small bar through the openings...

Still leaves me with that high pitched whine on acceleration from the same area. It could almost be compared with the spooling up of a turbo, Increases in pitch with engine rpm, but only lasts about 2-3 seconds then never returns while driving, until accelerating from a stop again. But that I probably should evaluate more carefully after a complete fluid drain, filter replacement and refill...

That will have to wait a little because next weekend I have to get the little W201 evo tribute car I have ready for sale. Poor thing sat in my driveway for the last two years...
---
Mercedes: '99 CL500, '86 500SEC, '96 SL500, '06 R500, '02 ML320, '78 450SEL
Porsche: '80 928S 5-Speed, '86.5 928S RogerBox '86.5 928S 5-Speed, '83 944
Others: '84 Callaway Alfa Romeo GTV6, '83 Tiara, '87 FZ

TJ 450

The high pitched whine is likely to be the front pump in the transmission. It seems to be quite common with a few miles on the clock. Definitely check the flex plate bolts though, as well as the transmission mount and tail shaft couplings. Also any exhaust heat shields and transmission linkages. Don't forget the control rod, as it has a little nylon bushing that disintegrates.

You're best living with the whine if it's the front pump, unless you feel like removing the trans. If it's shifting fine otherwise the I wouldn't worry.

Tim
1976 450SEL 6.9 1432
1969 300SEL 6.3 1394
2003 ML500

Zaxxon

Hi Tim!

Those are some great points, because I felt like it was a pump noise too, but never had any pumps fail on a Mercedes A/T, but everything I worked on so far were 722.6 transmissions, aside from the A/T in the 928s that were also built by Mercedes-Benz. Also never thought about the control rod. That's a good one too!

Thanks for your help!
---
Mercedes: '99 CL500, '86 500SEC, '96 SL500, '06 R500, '02 ML320, '78 450SEL
Porsche: '80 928S 5-Speed, '86.5 928S RogerBox '86.5 928S 5-Speed, '83 944
Others: '84 Callaway Alfa Romeo GTV6, '83 Tiara, '87 FZ

Zaxxon

I dropped the pan today, and as I almost expected, quite a few shiny bits in there. Everything pretty small, but enough for concern. Also some black "dust" most likely clutch material. Kind of odd for just 61k on the clock, but I guess things happen. The whine seems to be definitely the front pump. Did a flush, filter and refill, no magic betterment unfortunately. Also seems to be slipping a bit on take off.

So, it seems I am after a good used or comparable transmission and possibly also TC. I'll scour the local yards, but I don't think it'll have much success. Never know. Anyone got one laying around?
---
Mercedes: '99 CL500, '86 500SEC, '96 SL500, '06 R500, '02 ML320, '78 450SEL
Porsche: '80 928S 5-Speed, '86.5 928S RogerBox '86.5 928S 5-Speed, '83 944
Others: '84 Callaway Alfa Romeo GTV6, '83 Tiara, '87 FZ

daantjie

If you are planning on switching out the trans anyway, you can try dumping in a bottle of TransX just for kicks and see if it gets better.  Some folks claim amazing results, even just for the short term until you decide to replace. 
Daniel
1977 450 SEL 6.9 - Astralsilber

Zaxxon

I did that right after the road test. I used the equivalent Lucas product. But it didn't make a difference. I had good luck with it in the past too. It helped a few transmissions that weren't THAT great anymore, had slight slipping and such, but it didn't make a difference here. It really sounds like something is badly grinding away in the front pump.

I'll let it sit overnight and see how it is tomorrow (if the weather forecast is *hopefully* wrong and we're not getting a few inches of snow), but I have a feeling it won't make much of a difference. On a good note, from the looks of it, the transmission is fairly easy to swap, compared to some of my other cars...
---
Mercedes: '99 CL500, '86 500SEC, '96 SL500, '06 R500, '02 ML320, '78 450SEL
Porsche: '80 928S 5-Speed, '86.5 928S RogerBox '86.5 928S 5-Speed, '83 944
Others: '84 Callaway Alfa Romeo GTV6, '83 Tiara, '87 FZ

daantjie

Apparently TransX is way better than the Lucas "transmission fix" stuff.  But I guess you are way past the "snake oil" point ;D
If you are looking to swap, try Sun Valley in California, they have a very good reputation,  You ship your old trans to them and they send you a rebuilt one.  I have only heard good things about their service, worth a try methinks.
Daniel
1977 450 SEL 6.9 - Astralsilber

Zaxxon

Yea, unfortunately I fear I am definitely past that point. but that sounds good daantjie! I'll definitely look them up!
---
Mercedes: '99 CL500, '86 500SEC, '96 SL500, '06 R500, '02 ML320, '78 450SEL
Porsche: '80 928S 5-Speed, '86.5 928S RogerBox '86.5 928S 5-Speed, '83 944
Others: '84 Callaway Alfa Romeo GTV6, '83 Tiara, '87 FZ

Zaxxon

I ended up finding a 55k transmission with TC out of a '79 450SEL. Cheap enough even with shipping to take the risk. Apparently out of a runner and at least with a 30 day money back for the part itself, so we'll see!
---
Mercedes: '99 CL500, '86 500SEC, '96 SL500, '06 R500, '02 ML320, '78 450SEL
Porsche: '80 928S 5-Speed, '86.5 928S RogerBox '86.5 928S 5-Speed, '83 944
Others: '84 Callaway Alfa Romeo GTV6, '83 Tiara, '87 FZ