Hi,

Around 2pm this afternoon I decided to finally do my 82' 300TD's starter replacement. My starter has been intermittantly whirring (without clicking), preventing a start. It gets worse as the weather gets cold, so I'm heading it off at the pass and changing it while the weather is decent (at least, thats the theory).

After a huge struggle that is basically a miniature version of what you are about to read about the top bolt, I was able to get the lower bolt on the starter loose, but now the upper bolt is giving me hell (of course).

My first tactic was to connect my 3/8" 10mm allen socket to a universal joint, then about 18" of extensions, which I fed up alongside the transmission pan. To this I connected a breaker bar. The problem was that even if I got the socket seated well, the socket would pop out before the bolt turned. Now, in its defense, it would pop out while I was pulling incredibly hard, as hard as I could pull.

The next tactic was to improve my socket by making a new one. I cut a piece from a 10mm allen wrench, and slipped it into a 10mm impact socket. It would let me pull a little harder, but would still eventually slip out.

To get some more torque, I started using my pneumatic impact wrench, which puts out a modest 250ft/pounds of torque. Unfortunately, I could hammer away all I wanted, and the bolt would not loosen.

Then I tried the 'from the top' method. I removed the aircleaner assembly, the battery and tray, and the heat shield that is in the way. From here, I could get small wrenches in, and was able to do things like insert the 10mm allen 'nub' I had made into the bolt, then grab it with a 10mm box wrench or something. Unfortunately, pulling as hard as I could from underneath with a breaker bar meant that getting sufficient torque with a short wrench was not going to happen. The space is still too tight to get my 1/2" breaker bar in from above.

Then I went to a store, and picked up a 500 ft/pound impact wrench.

More attempts from underneath, and no luck. I could get the socket to stay in the bolt, but nothing would move the bolt.

Went to more extreme methods, and drilled a big hole in the firewall. Now I've got a straight shot to the bolt, but STILL can't get it to budge, with either breaker bar or impact wrench. I'm worried that my compressor can't put out the full CFM necessary for the new wrench, so I'm half tempted to take the car to one of the gas stations with free air, quickly remove their tire chuck and attach a quick release, and put on my impact wrench, and see if I can break the bolt loose there. (I could tighten the lower bolt again, just enough to hold things in place, start the car, take it to the station, break loose the top bolt, and then gently retighten, restart, drive home, and then remove both bolts). But of course, there is no guarantee I could do it, even with more CFM...

All this time I've been squirting it with PBlaster and intermittantly applying heat with a MAPP torch, as well.

At this point I'm running out of ideas, and I've been tackling this bolt for over 8 hours. I'm filthy as sin itself, and in dire need of a beer and hot meal, but I'm not happy aboutthe prospect of ending the night in defeat. Anyone got any great ideas?

peace,
sam

__________________
"That f***in' biodiesel is makin' me hungry."

1982 300TD Astral Silver w/ 250k (BIO BNZ)
2001 Aprilia SR50 Corsa Red w/ 5.5k (>100 MPG)

I struggled with that cap screw myself. With a 1/2" breaker bar (18") and all of my strength, I could not break it loose while working from the back of the transmission, using extensions. I used 1/2" extensions with an adaptor for the 3/8" bit on the end.

So, I got a piece of pipe to fit over the breaker bar that was about 24" length and there was just enough angle to get the contraption up in there and torqued enough to crack the bolt loose. When it let go I though I was a goner. There was a crack that sounded like something fractured. But, the bolt had budged and from then on it was downhill.

You need a 24" stiff pipe (1.5" diameter is nice) and just about all the strength you have. While doing this, you must make absolutely sure that the socket bit does not slip out of the socket head on the cap screw. I can't recall, but I probably used the universal in the set of extensions to be sure that the bit went squarely into the screw.

I'm not a fan of the impact wrench. Too much localized force on the inside of the screw. The chances of rounding it off are very high. You don't even want to think about the consequences of this.

It's a difficult and miserable job. You have my sympathy. In my case, life was much easier after the screws were removed because I did the job with the manifolds off the right side of the engine.

Well, I made another heroic attempt with the breaker bar, this time with a goodly piece of pipe over the end to give me a little more length. I seated the allen socket as securely as I could, used a universal to keep it straight, braced the extensions against the firewall, and pulled like heck. Like you, I heard a loud 'pop', but unlike you, it was the sound of the socket stripping the bolt, instead of the bolt loosening. Delightful.

There is still some usable grip inside the bolt head, but I'm done with it. I can't think of anything within my means that will make it better instead of worse. I suppose I'll just bolt the bottom back together, reassemble the topside, and then just hope the starter doesn't get any more intermittant than it is now. Man, what a day.

Theoretically, if I were going to proceed with a partially stripped bolt head, what the heck would I do? Get someone to mig weld a big bolt head onto the cap? Pull the engine? Hammer a slightly oversize allen into the hole?

Man, I hate situations like this..

peace,
sam

__________________
"That f***in' biodiesel is makin' me hungry."

1982 300TD Astral Silver w/ 250k (BIO BNZ)
2001 Aprilia SR50 Corsa Red w/ 5.5k (>100 MPG)

1984 300d Turbo
Lower The Trans 2-3 In. 2 Ft Ext To 10 Mm Socket Tap The End Into
The Top Bolt Remove The Four Trans Mount Bolts And Two Bolts
For Drive Shaft. Use Small Jack To Hold Up Trans Use A 10 In 2 By 4
Across Jack To Pan, Use 2 Ft Breaker Bar Use Jack To Move Breaker
Bar, It Will Pop. Diy Or Use You Foot On The Car Frame AND PULL ALSO
USE A FLEX EXT ON END OF SOCKET GET THEM AT ANY AUTO STORE
2-6 IN REMOVE GROUND ON BATTERY USE 17 MM SOCKET ON WIRE TO
STARTER, TURN FR WHEELS TO FULL RIGHT

Don't bother with the station tire compressor. It's just an oversized electric bicycle pump. It won't have enough CFM's to spin a wind wheel.

Drilling a hole in the firewall is cheating (But it's most likely the way I'd do it. )

Seriously, I'd MIG a good quality nut onto it. Drill out the inside of the nut so it just slips over the bolt head and chamfer that hole on the outside so the MIG gets good penetration. Make sure beforehand that nut will have a snug fit on the socket you will use.

__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

Great suggestions. Sometimes a new, higher quality hex driver bit works on rounded out situations. You will be surprised at the variance in actual size.

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )

I just had my starter replaced on my '85 300D. Like you, I got the bottom bolt loose but could not for the life of me figure out how to get that darned top bolt off. I tried extensions and universal drives to no avail. I finally took it to a shop a coworker knew of and they finally got it off. To their advantage they had a lift so the mechanic could stand under there and get a better angle on it while I was just lying on my back. I he used a universal drive, about two feet of extension, and about two feet of cheater bar. The sight of every mechanic in the shop standing under your car and shaking their head is never a good sign. He finally got it out, with that gut-wrenching "bang!" of the bolt breaking loose. They only charged me $90 for the labor, too. To me it was well worth it after my failed attempts to get the darn thing out. Sorry to hear about the stripped bolt. Its frustrating to try to fix something and only wind up making it worse. Don't worry. It'll work out. There are plenty of experienced mechanics here who I'm sure have dealt with something like this before.

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Seth

1984 300D 225K
1985 300D Donor body
1985 300D Turbo 165K. Totaled. Donor Engine. It runs!!!
1980 300SD 311K My New Baby.
1979 BMW 633csi 62K+++? Dead odo

For what it's worth, I had my mechanic replace my 300D starter. I watched him remove the upper bolt with the car on a lift. He has what looks like an extension about 3 feet long that is designed to flex and provide some instant torque (some Snap-on tool that costs $$$). With the rear tranny mount loosened, he was able to get a straight shot at the bolt head. Then, using a breaker bar, he flexed the extension a couple of times and gave it one good pull. The bolt broke loose on the first try. I never would have gotten it loose without a lift and the proper tools.

I may be mistaken, but if the starter is "whirring", that sounds more like the bendix drive is bad. Can the bendix be removed easily on your starter without the removing the whole starter/bendix assembly?

If your access hole is big enough, you may be able to cut off the head of the bolt with a Dremel tool.

By the way, when I replaced the starter on my 77 I used one universal joint, about 3' of extensions and a 3' breaker bar. I did not lower the transmission. It took all my muscle on the 3' bar and it was awkward getting it in the right position because there's only so much turning arc when the car is just jacked up about 18". Why are those bolts so tight?

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

As of this posting I am on my millionth try to get that top 10mm bolt out. I will forego any replication of frustrated attempts, but the following technique worked fine for the bottom bolt and tomorrow if it doesn't rain again I shall attempt the top bolt.

After securing a 10mm Allen wrench with a fitting and extension, I interfaced it with a 6 ton hydraulic jack between the ground and the extension. From a fairly safe distance I began to apply pressure and the bolt loosened immediately. Hopefully I won't have to drill a large whole in the chassis ( hadn't thought of that , but the idea has merit) and I hope to retain the necessary patience to not resolve to heavy artillery, but I am determined to get that top bolt loose.

More later, Leon

603A in a V126 is not the topic here. our starter is super duper easy.

__________________
James Marriott
2003 Buick Regal
1983 300D (228k, frau Auto)
1996 Suburban K2500 (192k, 6.5 turbo diesel/4WD towmaster 10,000)
www.engineeringworks.biz
1987 300SDL junker 170k
1982 300SD junker, 265k