I'm having trouble reinstalling the #4 glow plug on a 2006 E320 CDI. I got the old one out without incident. But the problem that I'm having installing is that my deep 10mm socket is to tall to clear the plastic cover (the vertical portion of it). While the horizontal portion of the cover detaches, that doesn't help my cause...the vertical portion stays pretty rigid. So I can't get the socket can go straight on the glow plug. Perhaps there's such a thing as a slightly shorter deep socket. Mine is 2.5" long.

I've tried getting the threading started with a piece of vacuum tubing but so far no success.

I'm sure this is, as much as anything, a simple tool question where I simply can't see the obvious solution.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 157k miles
06 E320 CDI "Rutherford", Black on Tan, 175k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 144k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 70k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Try using a long piece of fuel hose in place of the vacuum hose.
It will give better control on starting the threads.

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78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022

Photo?

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Greg
2012 S350 BlueTEC 4Matic
2007 ML 320 CDI
2007 Leisure Travel Serenity
2006 Sprinter 432k
2005 E320 CDI
1998 SLK230 (teal)
1998 SLK230 (silver)
1996 E300D 99k, 30k on WVO
Previous:
1983 240D, on WVO
1982 300D, on WVO
1983 300CD, on WVO
1986 300SDL 237k, 25k on WVO (Deerslayer)
1991 350SDL 249k, 56k on WVO - Retired to a car spa in Phoenix
1983 380 SEC w/603 diesel, 8k on WVO
1996 E300D 351k, 177k on WVO

Hope your are putting something on the threads of the Glow Plugs like Never-sieze, glow plug grease and it might be even regular wheel bearing grease is better then nothing at all. You goal is to eliminate corrosion.

If you Socket is too long is there enough on the end that goes over the Glow plug to shorten it? Like spark plugs it is bet so turn them in as far as you can by hand if that is possible to eliminate the chance of cross threading.

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84 300D, 82 Volvo 244Gl Diesel

https://images.google.com/ search you will see sites with videos and other forums like ours.

search= changing the glow plugs in a Mercedes 648

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84 300D, 82 Volvo 244Gl Diesel

I figured out that what I needed was a 1/4" drive 10mm deep...it's a half inch shorter. So I'm all set.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 157k miles
06 E320 CDI "Rutherford", Black on Tan, 175k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 144k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 70k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Had the exact same problem on the same #4 glow plug several weeks ago. Was using 3/8 inch deep socket which was too long. Took me awhile and then, Ah...Ha! Good thing there are different size ratchets.

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-- Chris

'95 E300, 216k miles, Silver Surfer
'05 E320 CDI, 138k miles
'07 S550 4matic, 69k miles

Gone but not forgotten:

'76 300D, 350k miles?, SOLD in 1995
'75 240D, 300k miles, SOLD in 1991